Identifying an Unknown Blood Type

The following case study has a student working with blood samples to identify their blood types (A, B, AB, and O). Consider the situation and answer the questions.

A student is given eight red blood cell suspensions, which contain only red blood cells, and the matching serum from each sample. (Serum is blood plasma in which fibrinogen has been removed.)

She is asked to identify each of the four different blood types present. To test these samples, the only materials she has at her disposal are a sample of type A red cell suspension and the serum from type A blood.

Describe the step-by-step procedure that she must use to identify the four different blood types present. In each step, interpret what it means if the cells in the sample clump together, or if they do not clump together.

I am mostly confused on what exactly "she has at her disposal are a sample of type A red cell suspension and the serum from type A blood." means… ? What is a A red cell suspension?

I already know that:

TYPE A: has anti-B antibodies

TYPE B: has anti-A antibodies

TYPE AB: has neither anti-A nor anti B antibodies

TYPE O: has both anti-A and anti-B antibodies.

The passage:

To test these samples, the only materials she has at her disposal are a sample of type A red cell suspension and the serum from type A blood.

means, I take it, that she has available two containers: One has red blood cells from a known blood-type A individual suspended in a neutral fluid such as saline solution. The other container has blood plasma (without red blood cells or fibrinogen) also from a known blood-type A individual.

These should be enough to determine the blood types of four individuals from the unknown test tubes (four pairs of test tubes, each pair being one with cell suspensions and one with plasma, coming from four individuals having different blood types).

Blood types: the not so bleeding obvious

Accentuate the positive, eliminate the negative … that’s the song I start humming whenever I’m asked for my blood type. That’s because mine is B positive—which is kind of cool, really. Life affirming, in a pop-psychology kind of way. But, apart from the warm fuzzy, what does this actually mean?

Like most people, I know that some blood types are more common, or rarer, than others. I know that giving blood is a really good thing to do, and that getting the wrong type of blood in a transfusion is bad news. But when it comes to the nitty gritty, things get a bit hazier. Like, what makes my B-type blood different from your O-type blood? Is my type of blood special or run of the mill? And what would happen if I needed a transfusion and got the wrong kind of blood?

Aside from the feelgood factor, what does my B positive blood type actually mean? Image source: Angie Muldowney / Unsplash .

Using Blood Typesas a Cheap Paternity Test

The earliest paternity test was a comparison of blood types. This analysis cannot provide absolute proof of fatherhood. But it can often eliminate a potential father.

Plus, you may already know each person’s type from medical records. In that case the cost is zero.

TIP: If a man was ever in military service, his type will be on his dog tags.

Even if you don’t already have this information for everyone, this approach may be less expensive than a DNA paternity test.

So you may want to identify the missing blood types before you incur the expense of a DNA paternity test.

Briefly, here’s how blood typing works.

There are four common values: A, B, AB, and O.

If you know the mother and child’s type, then you can use the following chart to narrow the list of possible types for the father.

Find the child's value in yellow and the mother's value in blue. Read down the child's column and across the mother's row to find the green cell where they intersect.

The letters listed in that cell are the possible ABO groups of the father.

For example, if the child is A and the mother is O, the father MUST be A or AB. It is biologically impossible for a man with B or O blood to have fathered this child.

NOTE: The two blank cells represent impossible combinations between mother and child, regardless of the father.

Important Limitations of Blood Types

As you can see in the chart, there are some combinations of mother and child that show all four possibilities and cannot, therefore, eliminate any possible father.

The most important limitation is that knowing this information can, at best, only eliminate someone. By itself, it cannot prove that any given man is the child's father.

However, if the mother knows there are only two possible candidates, eliminating one of them will tell her that the other one is the father.

If this doesn’t resolve the question—-or if you need a positive paternity test for legal purposes—-you must still get a DNA paternity test.

While many companies can provide such a test, the one I am most confident in isꃪsyDNA.

TIP: If your paternity issue involves child support or custody issues, you need to order their LEGAL paternity test that is court admissible. If this knowledge is just for personal information, the home test kit is sufficient.

What if the Father is Unknown?

In some cases a child's biological father may be an unknown man. In that case DNA testing can solve the mystery, just like it has for thousands of adoptees. Read my page on Find Birth Parents to learn more.


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Blood Types

The first question to ask and indeed to answer when looking into the area of blood types is: what is blood?

What is Blood?

Blood is – for the most part – the liquid part of the human body, which is called Plasma and this Plasma contains proteins, clotting factors, electrolytes (which carry small electrical stimuli) and a varying number of cells.

These cells when broken down are:

  • Platelets: Small cells involved in the clotting process which enable the flow of blood to be kerbed if a small cut or wound is inflicted
  • Leucocytes: The blood’s white cells.
  • Erythrocytes: The blood’s red cells.

After a wound has been inflicted and clotting has taken place the remaining fluid – known as serum – is a discoloured yellow and is still full of proteins and enzymes – this serum as we shall discuss is useful in the forensic process.

Blood Groups and Crime

Now that we have established in a little more detail what blood actually is it is important to look at how the different blood groups are made up and also how these blood types are used in the categorisation of suspects in crimes where blood and other bodily fluids are secreted.

Forensics use a system called the ‘ABO System’, which is a system that measures antigens antigens within the body determine blood type and are normally categorised as either A or B. Antigens categorised as being Type A are found in an individual’s red blood cells whilst the same equation can be applied to someone of Type B blood grouping.

Also within the blood typing system there are Rhesus antigens, which can be categorised as Type D should an individual’s red blood cells have these Rhesus antigens they are classed as RH Positive and likewise if they do not appear they are classified as RH negative (or Rhesus Negative).

At a crime scene where there has been blood spilled – either that of the victim or that of the assailant – and indeed in some instances that of both parties a serologist will take blood samples in order to identify who’s blood belongs to whom.

Taking the aforementioned factors into consideration makes this process somewhat less complex than it perhaps sounds and this blood grouping system is also used to determine from which blood group the individual’s parents were categorised.

Parents may have different blood from their children and indeed siblings may also have different blood groups but through the use of DNA fingerprinting it is possible to draw up certain characteristics that are shared between the father and mother and their offspring this is called Mitochondrial DNA and can be found all the way through a family’s bloodline over many generations.

report this ad These blood types although used as a means of collating DNA evidence can be used more as a means of identification that an admission of guilt. As the discovery of a blood type through the use of a sample is useful it is not an exact enough science to prove that an individual has been the perpetrator of a crime on its own.

Other such evidence – as we have already mentioned – DNA evidence, trace evidence and eye witness accounts must all be used to compile a picture that can be used in any prosecution case.

20 Amazing Facts About Your Blood Type

Knowing more about your blood type can be beneficial to your health in the long run.


Memorizing your blood type is critical for all sorts of reasons, from knowing who you can accept blood transfusions from to who you can donate your blood to. Not to mention the role it plays in your likelihood of contracting COVID-19. And now, as doctors and scientists do increasingly more research on how a person's blood type can affect their health, there's even more of an incentive to pay attention to whether you're A, B, AB, or O—and whether you're positive or negative, too.

For example, recent studies have found that a person's blood type can mean anything from an increased risk of depression to a higher likelihood of developing diabetes. Curious about what your own blood type means? Keep reading to find out. And for more incredible information about your body, check out 23 Facts About Your Brain That Will Blow Your Mind.


Although people with type O blood are more susceptible to bites, they can thank their genetics for one thing: protection against malaria. Oddly enough, scientists have found that folks with type O blood seldom die from malaria, seeing as the RIFIN protein—the protein that causes malaria—is less able to bond to type O blood cells and therefore cannot do as much damage.


If you have type O blood, then your heart is in luck: According to research presented at the 2017 World Congress on Acute Heart Failure, individuals with this blood type are less likely to suffer a heart attack or stroke. The bad news? Individuals who are type A, type B, or type AB—in other words, some 63 percent of the overall population—have a 9 percent increased risk of both coronary and cardiovascular events. And for more things you can do prevent a serious medical condition, check out 30 Crucial Ways to Lower Your Heart Attack Risk.


Stomach cancer and type A blood seem to go hand in hand. That's according to a 2015 study published in the journal Cancer Epidemiology, which found that people with type A blood were 38 percent more likely to develop stomach cancer than those with type O blood. And for more things you should know about your abdomen, check out This Is Everything Your Stomach Is Trying to Tell You About Your Health.

Though non-A blood types are relatively less likely to get stomach cancer, they still have to worry about pancreatic cancer. In the same 2015 study, researchers found that all non-O blood types were at a higher risk of pancreatic cancer, and subjects with type B blood were 59 percent more likely to come down with the cancer. And for more on the symptoms of this particular condition, check out 13 Warning Signs Your Pancreas Is Trying to Tell You Something's Wrong.


If your blood type is AB, then you'll want to keep a close watch on your cognitive health. One 2014 study published in the journal Neurology analyzed the relationship between blood type and brain health and found that people with type AB blood had an 82 percent higher risk of cognitive impairment. And for more on protecting yourself from cognitive issues down the road, check out 40 Habits to Reduce Your Risk of Dementia After 40.


The minority of the population who is Rh negative is at a higher risk of certain mental health issues. A 2015 study of more than 3,000 subjects published in the journal PLoS One found that "Rh negative men more often reported certain mental health disorders including panic disorders, antisocial personality disorders, and attention deficits."


In addition to mental health issues, people with Rh-negative blood types are also more prone to developing allergies. In the same PLoS One study, researchers found that subjects with Rh-negative blood were slightly more likely to have skin allergies. And for more helpful information delivered straight to your inbox, sign up for our daily newsletter.


Whether or not you're Rh positive or Rh negative could have an impact on your pregnancy. According to the American College of Obstetricians and Gynecologists, problems can occur when a woman is Rh negative and her fetus is Rh positive, as this can result in something called Rh incompatibility.

"If the blood of an Rh-positive fetus gets into the bloodstream of an Rh-negative woman, her body will understand it is not her blood and will fight it by making anti-Rh antibodies," the organization explains. "These antibodies can cross the placenta and try to destroy the fetus's blood. This reaction can lead to serious health problems and even death in a fetus or newborn."


While type O is the most common blood type overall, it's especially prevalent in the Latino-American community. According to the American Red Cross, approximately 53 percent of Latino-Americans are type O+ and 4 percent are type O-.


That statistic about the Latino-American community makes sense, seeing as negative blood types—whether type A, type B, type AB, or type O—are few and far between. In fact, according to the Oklahoma Blood Institute, only about 18 percent of the total U.S. population has a negative blood type.


Wondering who pioneered this science in the first place? In 1909, Austrian scientist Karl Landsteiner became the first person to properly identify the four main blood groups. It's thanks to his research that we now know which blood types to use (and which not to use) with patients in need of transfusions. In 1930, he was rewarded for his contributions when he was given the Nobel Prize for Physiology or Medicine.


One of the many things that can contribute to a woman's fertility is her blood type. At the Yale University Fertility Center in 2011, researchers analyzed subjects' levels of follicle-stimulating hormone (FSH) and found that women with type O blood were more likely to have higher FSH levels. The problem is that high levels of FSH are typically an indication of a diminished ovarian reserve, which means that a woman with type O blood might be less likely to get pregnant as she gets older.


Have you ever wondered what makes your blood type A, B, AB, or O? Turns out, it's all about the sugar.

The blood types are named after antigens that are found on the surface of your red blood cells. These antigens are simple chains of sugars, according to Stanford School of Medicine. "The A flavor makes the A sugar, and the B one makes the B sugar. It turns out that the O flavor doesn't make any sugar," according to Stanford. "Someone that's 'AO' will be type A, because the O flavor of the gene makes no sugar. This person only has the A sugar."

But what about the positive or negative element? Well, that's all about the Rhesus factor (or Rh factor). If you don't have the Rh factor, your blood is negative. If you do have it, your blood is positive.


Type O- blood is in extremely high demand at hospitals—not just because it's one of the rarest blood types, but also because it's the "universal donor." Because O- is Rh-negative, it can be given to people with both positive blood types and negative blood types. These folks can also donate to A, B, and AB blood types. Though a foreign antigen could cause the body to attack, there are no antigens present in type O blood, so there's nothing to attack.


If your blood type is AB+, then you're in luck. This blood type is known as the "universal recipient," seeing as people who have it running through their veins can receive blood from any type A, type B, type O, or type AB donor. Because type AB blood contains both A and B antigens, as well as the Rh factor, it can tolerate a transfusion from anyone on the ABO spectrum.


Though doctors and scientists aren't entirely sure what causes cancer, one thing that they do know is that people with type B blood are more likely to develop certain cancers. In fact, one 2012 study published in the World Journal of Gastroenterology found that type B blood individuals were about 50 percent more likely to be diagnosed with both esophageal and biliary cancers.


Type A, type B, and type AB blood types have been shown to have higher levels of the proteins von Willebrand factor and factor VIII, both of which contribute to clotting. In fact, a 2007 study published in the Journal of Thrombosis and Haemostasis found that people with type A, B, or AB blood were 31 percent more likely to develop venous thromboembolism, a condition in which a blood clot forms in the leg, groin, or arm and lodges itself in the lungs.


When French researchers analyzed data from some 82,000 women in 2015, they found that those with type A blood were 10 percent more likely to develop type 2 diabetes and those with type B blood were 21 percent more likely to develop the disease. The scientists hypothesize that a person's blood type may play a role in their gut microbe makeup, which could, in turn, affect metabolism and contribute to diabetes risk.


According to 2015 research published in the International Journal of Science, Spirituality, Business and Technology, "people [in Japan] strongly believe that the blood type influences one's personality, weaknesses, and strengths."

Per these beliefs, people with type A blood are calm and collected, artistic, and polite people with type B blood are practical, goal-oriented, and strong-willed people with type O blood are outgoing, energetic, and outspoken and people with type AB blood tend to have characteristics on both sides of the spectrum.


Many factors contribute to whether or not you are a magnet for mosquitos, including your blood type. In one 2004 study published in the Journal of Medical Entomology, researchers found that one species of mosquito—Aedes albopictus—landed on 83 percent of subjects with type O blood and just 47 percent of subjects with type A blood. Scientists believe that mosquitos may be able to sense the sugars some people secrete through their skin based on their blood type.

How to Write Microbiology Unknown Lab Report | Microbiology Lab Paper

In the past, it has been vital to distinguish the identities of microorganisms in the world. Knowing their identity has aided in diagnosing numerous diseases and has discovered the most beneficial treatment. The purpose of this study was to identify a Gram positive and a Gram-negative bacterium from a mixed culture. The methods that were previously studied and practiced in the Microbiology laboratory class were applied in order to identity two unknown bacterium.

The lab instructor gave out a test tube labeled number 118, which consisted of two unknown bacteria, one Gram negative and one Gram positive. Sterile techniques were followed while performing precise instructions as stated in the referenced Laboratory Manual.

The first procedure performed to isolate a pure culture from the mixture in the test tube onto a solid media. A sterile inoculating loop collected bacteria from the test tube with the unknown, and streaked a series of zigzag lines along two nutrient agar plates, using the Quadrant Streak Method. These plates were incubated for two days to allow the bacteria to grow. Both plates were studied, noting their characteristics, which were recorded in a journal. One distinct colony grew and a Gram stain was performed on the isolated colony. The Gram stain procedure was carefully followed according to the referred Laboratory Manual. Gram-negative rod shaped bacteria were identified using the microscope. The glass slide and nutrient agar plate were labeled Gram negative and were then stored in the refrigerator. Gram-positive bacteria did not grow. After determining the Gram-negative reaction, specific tests were performed.

In order to identify the Gram-positive bacteria, a sample from the original test tube was streaked on a Mannitol Salt Agar plate and placed in the incubator at 37 Degrees Celsius. There was only one type of bacteria that grew. This was isolated and a Gram stain was performed. Both of the plates were labeled and stored in the refrigerator. Gram-positive cocci shaped bacteria were identified using the microscope. Several biochemical tests were chosen based on the identification table which was given by the lab instructor. These tests and results were recorded on the flow chart and the tables on the following pages for the Gram-negative and Gram-positive bacteria.

Table one and two list the tests, purposes, reagents, observations and results.

All of the following tests were performed on these unknowns:

Unknown number 118 was streaked on a nutrient agar plate. A Gram stain was performed. It was determined that it was a Gram negative rod. Gram positive did not grow. In order to identify the Gram positive bacteria, a sample from the original test tube was streaked on an MSA plate. A Gram stain was performed which identified Gram positive cocci. Table 1 and Table 2 list all of the biochemical tests, purposes, reagents, observations and results. The results are also displayed in a flowchart.

TABLE 1. Gram Negative (-) Tests

To determine the gram reaction of the organism

Crystal violet, Iodine, Decolorizer, Safranin

To determine if organism is able to utilize citrate as carbon source

Color change from green to blue

To determine fermentation of galactose

Negative galactose fermenter

To determine if it ferments mannitol

Negative mannitol fermenter

To determine if it hydrolyzes gelatin

It turned to liquid after refrigeration

To determine if it ferments mannitol

Medium changed from red to yellow

Positive Mannitol fermenter

To determine the gram reaction of the organism

Crystal violet, Iodine, Decolorizer, Safranin

To determine if urease hydrolyzes urea

To determine if catalase is present

The result of the tests for Gram negative led to the identification of Pseudomonas aeruginosa. A Gram stain discovered that the bacteria were rod shaped. A Simmons Citrate test was performed and the positive result narrowed it down to three bacteria. After a Gelatin and a Galactose test were performed, the only bacterium that remained was Pseudomonas aeruginosa. A negative result on a MSA plate verified this result. This was the correct identification because all of the other Gram negative were eliminated. There were no problems encountered in finding this conclusion.

The result of the tests for Gram positive led to the identification of Staphylococcus aureus. A sample from the unknown bacteria was streaked on a MSA plate. A Gram stain was performed which verified Gram-positive cocci. This was a positive result for mannitol fermentation which narrowed it down to two bacteria. A negative urea test was performed, which also narrowed it down to the same two bacteria. A positive catalase test verified that the bacteria in the unknown would have to be S. aureus. This was the correct identification because all of the tests performed, identified S. aureus as the unknown Gram positive bacterium. The only problem I encountered was during the isolation streak, Gram positive could not be isolated on a nutrient agar plate. However, it did grow on a MSA plate and was isolated on a nutrient agar plate.

S. aureus is a bacterium that is frequently found in the respiratory tract and on the skin. It is a common cause of skin infections, diseases and food poisoning, and is not always pathogenic (Tolan, 2011). Sometimes, disease-associated strains produce toxins which promote serious infections in the body. These toxins have proteins that activate antibodies which causes resistance. This emergence of resistance has led to MRSA (Methicillin Resistant S. aureus), and is a worldwide problem.

Forensic Science Lesson Plans

Topics Available
Daily CSI Challenges Crime Scenes & Testimonial Evidence Physical Evidence Fingerprinting
Impression Evidence Hairs & Fibers Chromatography Blood Basics Forensic Entomology
Forensic Anthropology DNA Evidence Arson Investigation CRASH Unit
CSI Adventure (Geocaching Activity) Supply Companies & Supply List

During the 2006-2007 school year I started teaching a 9-week course on Forensic Science as one of our 8th grade activity classes. A brief outline is available in PDF format - Quarter Outline and a list of supplies is available at the bottom of this page. Listed below are the powerpoints, worksheets, and other resources I use during the class. I have a SmartBoard in my classroom and many of the presentations (unit and review) are set up so students can help me fill in the answers as we discuss the notes or while they check their worksheets. Please e-mail me if you have any questions.

R eference Cards
I have created reference cards for many of the units/activities listed below, which are designed to replace the student worksheets and some lab pages for those units. The cards are printed on card stock (back-to-back) and laminated for student use. Students use overhead markers to add notes to the pages as we discuss each lesson and keep them to review for the unit quizzes. (You could also have students record their answers in a lab notebook rather than write on the pages.) At the end of the unit, they clean them off with a wet cloth and turn them in so they are ready for the next class! Less paper wasted and less time copying - a double bonus! In addition, the reference card format will allow special education students (and other students with learning challenges) to focus on the lesson and avoids possible frustration at trying to keep up with the class notes. They will have all the information they need in one place.

Daily CSI Challenges

I start each class period with a warm-up activity targeting forensic science concepts and other skills (observation, problem-solving, etc.) The challenges are in the form of PowerPoint presentations and include spot-the-differences puzzles, mini mysteries, trivia challenges, and vocabulary builders. I have also created several warm-ups that incorporate CSI-related videos that are available online.

Unit 1: Crime Scene & Eyewitness Basics

During this unit students learn basic vocabulary associated with crime scene analysis as well as explore testimonial evidence (eyewitness accounts and FACES facial composites software to create - see the list of supply companies at the bottom of this page.)

Also available .

Reference Cards : Crime Scene Basics (PDF) & Eyewitness Basics Card (PDF) - These handouts replace the worksheets for Crime Scene Basics and Eyewitness Basics.

Other General Resources:

Forensic Science A to Z Challenge (PDF) - Students must use clues to identify forensic science terms and then find them in a "bent word" style word search. They use the letters that remain in the puzzle to figure out a mystery word.

Memory Match Game (PDF) - This game challenges a student's ability to remember what they've seen as they examine cards with a variety of patterns on them. Game rules and pattern cards are provided in the download.

FBI Crime Lab (PDF) - Thanks to Stephanie Vallejo for sharing this worksheet for use with the History Channel's FBI Crime Scene DVD. Check out my new version of the FBI Crime Lab video worksheet that includes discussion questions for each section. The DVD is available through the Amazon or the History Channel. It can also be found HERE.

CSI Effect - A good article to start a discussion on real forensic science vs. TV versions.
Science Friday: Finding Fault with Forensics - Visit this page for more information on the topic and a podcast to share with your students.

Unit 2: Physical Evidence

During this unit students explore the various types of physical evidence that can be found at a crime scene and learn how they are used to help investigators. I usually do the introductory lesson to provide an overview of many types of physical evidence and then spend time investigating several of them in more detail, such as fingerprints, impression evidence (tire tracks), hairs & fibers, chromatography, blood evidence. and DNA.

Reference Card : Power of Evidence: Physical Evidence Card (PDF) - This two-sided handout replaces the worksheet listed above.

Other Physical & Trace Evidence Resources:

Power of Evidence Challenge (PDF) - Challenge your students to this word search/scramble using terms discussed in the Power of Evidence presentation.

Forensic Files Graphic Organizer (PDF) - Thanks to Luann Snider for submitting this worksheet that can be used with any of the Forensic Files episodes. I also have the Forensic Files Episode Worksheet available that can be used with any of the Forensic Files episodes.
Notes: Worksheets (includes answer key) are available for the following episodes: Tourist Trap (PDF), Past Lives (PDF), Zodiac Killer (PDF), Over & Out (PDF). You will need to find them on YouTube as the previous links I had do not work.

Christmas Cookie Mystery - Use this lesson listed on the Chemistry Lessons page to investigate white powders. The lesson can be adapted to fit any holiday in order to be used at other times of the year.

Murder & a Meal (PDF) - Thanks to Camron Stanley for sharing this lab investigating the science of vomit! The download includes student worksheets and teacher notes.

Fingerprinting Basics

During this unit students learn how to identify the different fingerprint patterns as well as other details that help investigators match fingerprints. They are able to practice making and lifting prints and are challenged to match unknown and known in the Fingerprint Challenge. I purchased ink pads, black powder, brushes, and other materials to make several kits to allow students to work in small groups. See the list of supply companies at the bottom of this page.

NOTE: I highly recommend the magnetic fingerprint wands and dust if you have the money available to purchase them. They are less messy than the traditional black powder and fiber brushes.

Reference Card : Fingerprint Basics Card (PDF) - This two-sided handout replaces the worksheets for all of the fingerprint lessons.
Questions about the reference cards? See the note at the top of this page.

Fingerprint Guide (PDF) - This one-page handout includes examples for all of the ridge patterns and characteristics discussed in the fingerprinting lessons.

Other Fingerprinting Resources:

Fingerprint Challenge (PDF) - Students use their investigative skills to match fingerprint samples.

Fingerprint Analysis (PPT) - I use this activity with my students to analyze the distribution of fingerprint patterns in each class. After students complete the My Prints worksheet and classify their prints, they complete the top section of the Fingerprint Analysis worksheet. We calculate the percentages for each pattern and discuss how it relates to the expected percentages presented in class. We also analyze the distribution of patterns for males vs. females and discuss the results after students have completed the bottom section of the worksheet.

My Toe Prints worksheet (PDF) - Students are always interested in examining their toe prints to see how they compare to their fingerprints. Instead of using the incapax from the fingerprint unit, the students create their own "ink" by rubbing pencils on an index card and then pressing it to their toes. They use a piece of clear tape to lift the print and tape it to the correct spot on the worksheet.

Lip Print Activity (PDF) - Thanks to Dina Sbarra for sharing her lip print mystery activity. She went around the school and got lip marks from several teachers at her school on paper and then put them in sheet protectors. She had one teacher also mark their lips on a plastic cup (the criminal that destroyed her room). She toilet papered my room and the students had to find out who did it. She put the lip prints on the screen so they could look at the various types to help them classify the lip prints and identify the one from the culprit.

Impression Evidence

I use this presentation to introduce the topic of impression evidence and then students investigate tire tracks, tool marks, and shoe prints.

Reference Card : Impression Evidence (PDF) - This handout replaces the student worksheet for the introductory presentation and may be used as a guide for the challenges listed below.
Questions about the reference cards? See the note at the top of this page.

Tire Tracks Challenge (PDF) - This lesson idea was submitted by Sandy Powell, a member of the Middle School Science Yahoo Group. The activity challenges students to match tire tracks of 8-10 small toy cars. Teacher information, a student worksheet, and a sample page of my challenge are provided in the download. A PowerPoint is available to introduce the activity and challenge.

Tool Marks Challenge (PDF) - This activity challenges students to match tool impressions from a set of 12 tools. Teacher information and a student worksheet are provided in the download. Also available . my challenge page and a PowerPoint to introduce the activity and challenge.

Bite Mark Evidence (PDF) - This activity allows students to practice making and analyzing bite mark impressions using stryrofoam plates and a variety of soft candy. This activity goes along with the material presented in the introductory presentation listed above. A PowerPoint is available for this activity. NOTE: As with any lab involving food, be aware of any food allergies that may be a concern with your students.

Forensic Files: Tourist Trap - This episode from Forensic Files fits well with the impression evidence unit as it includes analysis of bite marks. Students complete the worksheets as they watch the Past Lives episode from Forensic Files DVD. The DVD set is available for rent from Netflix and may be found at online stores. Worksheets (includes answer key) are available for the following episodes: Past Lives (PDF), Zodiac Killer (PDF), Over & Out (PDF)

Hairs & Fibers

Hairs & Fibers (PPT) - I use this presentation to introduce the use of hairs and fibers as evidence. This unit includes an "up close" look at hairs and fibers using microscopes and an assortment of prepared slides. At the end of the lesson, I have students complete the Hair & Fiber Challenge to test their ability to identify various samples.

Reference Card : Hairs & Fibers (PDF) - This two-sided handout replaces the student worksheet for the presentation.
Questions about the reference cards? See the note at the top of this page.

Hair Lab Worksheet (PDF) - Students examine their own hair sample as well as other animal hairs to complete this worksheet.

Hair & Fiber ID Lab Worksheet (PDF) -Students use microscopes to draw pictures of 6 hair and 6 fiber samples.
NOTE: I created slide sets of 9 animal hairs and 6 fibers for students to use for this activity. A worksheet for this number of samples is also available.

Hair & Fiber Challenge (PDF) - I used my microscope camera to capture images of the various hairs and fibers the students observed in class. I printed several sets of this worksheet on card stock and laminated them to keep them for future classes. I challenge the students to use their notes and observation pages to identify each one.


During this lesson students learn about the use of chromatography in crime investigations and use paper chromatography to test black markers. At the end of the unit, I use four of the tested markers to create a Mystery Pen challenge. The students test the four mystery markers and compare them to the samples they previously tested. The challenge is set up as a race to see which student team can be the first to correctly identify them.

Reference Card : Chromatography Basics (PDF) - This two-sided handout replaces the student worksheet for the presentation.
Questions about the reference cards? See the note at the top of this page.

Also try this one . Permanent Marker Chromatography - We used permanent markers and rubbing alcohol to "decorate" our lab aprons or white t-shirts that the students brought to class.

Blood Basics

During this unit students learn about the basics of blood evidence. From the composition of blood and blood types to bloodstain pattern analysis, students investigate how blood evidence can be used in a crime investigation. I use simulated blood samples purchased from Ward's. See the list of supply companies at the bottom of this page.

Need a cheaper version of the Blood Typing Lab? The version listed below uses milk, vinegar, and water instead of the regular simulated blood kits available from the science supply companies.
Presentation: "Ernie's Exit" Blood Typing Lab - "Cheap" Version (PPT)
Worksheet: Blood Typing Basics - "Cheap" Version (PDF) (Includes teacher notes)

Presentation #3: Bloodstain Science (PPT)
Worksheet : Bloodstain Science Student Notes & Lab (PDF) & Angle Guide (PDF) (Needed for Part 4 of lab)
EDPuzzle: Blood Evidence 2018 (PDF) - Updated worksheet using EDPuzzle videos to introduce the blood spatter unit. The videos are listed in the Blood Basics setion on the Forensic Science page at the Kid Zone

Reference Cards :
Blood Basics Card w/ Blood Typing Lab - This two-sided handout replaces the worksheets for the first two presentations and blood typing lab.
Bloodstain Science Card with Blood Spatter Lab - This two-sided handout replaces the worksheets for the Bloodstain Science presentation and lab.
Blood Basics & Bloodstain Science Card (PDF) - This two-sided handout goes with the Blood Basics, Blood Typing, & Blood Spatter presentations. It does not include the lab sheets - you will need to print those out separately.
Questions about the reference cards? See the note at the top of this page.

Other Resources for Blood Evidence:

Blood Typing Booklet - Thanks to Christina Beatty for sharing her booklet that she uses with her students to help them understand blood typing. Materials available: Blood Typing Booklet , Booklet Cut-Outs , and Booklet Key

DNA Evidence

During this unit students learn about DNA and its use in forensic science. After discussing the information on the reference card, students create DNA keychains, which are used for an identification activity in which students have to match their keychains with a paper model. Other lessons and activities are listed below.

Presentation : DNA Evidence (PPT)
Reference Card : DNA Evidence (PDF)
Student Worksheet:
DNA Evidence (PDF)

Other Resources:

PBS Learning Media - Forensics - A great lesson with links to additional project ideas from their archives. Use their Who Ate the Cheese - Students simulate electrophoresis and DNA fingerprinting to solve a crime.

DNA Resources - Check out the collection of links available at the site for activities investigating DNA.

Also check out the online activites and information on the Forensic Science page at the Kid Zone.

Unit 3: Forensic Entomology

During this unit students learn about forensic entomology and its use in investigating crime scenes.

Reference Card : Forensic Entomology Card (PDF) - This two-sided handout replaces the worksheet for the entomology lesson.
Questions about the reference cards? See the note at the top of this page.

Online Lessons & Resources for Forensic Entomology :

Crime Solving Insects (PDF) - This unit from the 4-H organization provides a wealth of information for teaching forensic entomology.
1 - I have developed a PowerPoint presentation, activity card (notes on front & lab page on back), and case cards to go along with this unit. I set up 6 "evidence" packets for each of the four cases - pipe cleaner samples of "maggots" and "pupae" along with a case card. I laminated the activity cards and students will use overhead markers to record their data and write the answers to the questions.
2 - I also did the optional activity outlined in the unit over the summer to provide real maggot and pupa samples for the students to examine as we disscussed the Forensic Entromology PPT. I collected a variety of maggots (species and sizes) as well as pupa and preserved them in glass vials with 50% isopropyl alcohol.

Forensic Entomology Unit - An excellent resource for junior high and high school students includes background information, case studies, and a game involving forensic entomology.

Visible Proofs: Entomology in Action - This lesson introduces students to the blow fly's life cycle and the accumulated degree hour (ADH) used by forensic entomologists for estimating the time of death.

Unit 4: Forensic Anthropology

During this unit, students learn to identify the main bones in the human body as well as investigate the role of forensic anthropologists in crime solving. The presentation includes links to several online videos along with other information and two activities.

Introductory Presentation: Bone Basics (PPT)

Activity Materials:
Bag O' Bones
- I purchased sets of bones from an online company for use with this activity. You will also need large butcher paper.
Bone Challenge - I prepared several sets of the skeleton cut-outs. You will also need blindfolds for the students and timers.

Other Resources:

Forensic Files Past Lives (PDF)- This episode from Forensic Files fits well with the anthropology unit as it involves the investigation of human remains by Dr. Bill Bass. Students complete the worksheets as they watch the Past Lives episode from Forensic Files DVD. The DVD set is available for rent from Netflix and may be found at online stores. Worksheets (includes answer key) are available for the following episodes: Tourist Trap (PDF), Zodiac Killer (PDF), Over & Out (PDF)

Kids Discover - Bones Magazine - A great resource available from the Kids Discover store that provides a good background of information about bones, joints, and much more. I purchaed a set of 15 for the students to use in pairs and created a worksheet to use with the magazine.

Unit 5: Arson Investigation

Through the help of our local fire department, students explore the basics of fire science and arson investigation. I also include lessons on fire safety and reinforce the fact that playing with fires can cause major damage and deaths. If possible, have a member of your local fire department present a fire safety program for your students.

Reference Card : Fire Science Card (PDF) - This two-sided handout replaces the worksheet for the Fire Science lesson.
Questions about the reference cards? See the note at the top of this page.

Unit Review : Fire Basics Review (PDF) and Fire Basics Review Answer Key (PPT) - Thanks to Christopher Hunter for sharing these materials.
Unit Assessment : Fire Basics Quiz (PDF) - Thanks to Christopher Hunter for sharing this quiz.

Other Resources :
20/20 Arson Investigation (PDF) - Thanks to Dana Long for sharing this video and worksheet that investigates the science of arson investigation. Update 2016: The video is available at
Flame Test
Flame Test Video at YouTube
Fire Safety Checklist from

Unit 6: Accident Reconstruction

During this unit students investigate Newton's Laws of Motion to analyze an accident scene to determine the sequence of events that lead up to the accident, explain damage resulting from the accident, and "solve" cases. I use activities from CRASH: The Science of Collisions, which is geared towards the high school level, but several of the activities targeting Newton's Laws can be used at the junior high level. Our district purchased the CRASH kit and I share it with the high school physics teacher. Many of the lessons could also be incorporated into driver's education classes. Use the contact form on their website to see if your high school can receive the program for free!

Other Resources:
Understanding Car Crashes: It's Basic Physics - Lessons and videos are available on this page. Scroll down to find the information and see the other resources available.

CSI Adventure (GPS)

I developed this geocaching activity for use with the CSI summer camp program at the Smithsonian in DC. For this activity, teams of students use GSP receivers to find 10 "evidence" caches. Each cache contains a cache card with 3-4 questions the students must answer or tasks they need complete. Each cache has a different theme and relate to the material the students investigated during the camp. After a team completes a cache and has all the correct answers, they are provided with a clue card that will help them determine the next waypoint in the adventure.

Supply Companies - The links below are provided to give teachers information about the forensic science supplies I use with my classes.

My Supply List - Includes links to the supply companies and item numbers along with the amounts of each I purchased for my classes.

Ward's - A large selection of resources for a forensic science class, including the Forensic Detectives Lab I use in my classes. I also purchase my simulated blood kits from them.

Educational Innovations - Visit the "Forensic Kits" area for the Ward's Forensic Detectives Lab that includes an assortment of materials and the FACES software I use for facial composites. I have also had good luck with their Perfect Ink fingerprint ink pads listed on the "Genuine Forensic & Crime Scene Materials" page.
NOTE: Use Ultimate Flash Faces as an alternative for the FACES software.

Lynn Peavey - My source for fingerprint brushes and other fingerprinting equipment. Good prices and service!

Cafe Press - My favorite site for CSI t-shirts!

Precision Forensic Testing - Visit this site for an assortment of great kits for your forensic science program.

Also available . Lesson Plan Links for Forensic Science
Links to my favorite online resources for lesson plans, activities, and worksheets.

Additional Online Resources

Human Genome Project
This site, entitled, “DNA Forensics”, is presented by the Human Genome Project. It provides a comprehensive overview of the topic covered in this BLOSSOMS lesson.

Learn.Genetics: Gel Electrophoresis
This presentation on DNA forensics is provided by “Learn.Genetics” of the Genetics Science Learning Center at the University of Utah.

This is the Learn.Genetics main site, providing links to a wide range of resources for learning about genetics.

MIT BLOSSOMS video: Visit to Police Identification Lab
Watch optional video: Visit to Police Identification Lab in Cambridge, MA to see how DNA is extracted from evidence at crime scenes.


UC Irvine Pathology Services has established a uniform policy for specimen acceptance/rejection that:

  • Has a positive impact on patient care
  • Protects specimen quality
  • Eliminates risk of exposure to the healthcare worker
  • Complies with all accreditation standards
  • Patient name
  • Patient medical record number, with check digit
  • Patient location
  • Collection date and time
  • Specimen type and/or source
  • Test required (note any special handling required)
  • Ordering physician

For patient safety, it is essential that the following be adhered to when submitting blood specimens for CROSSMATCHING purposes. Use special pink-top (EDTA) tubes.

  1. Take a Crossmatch/Transfusion form, patient printed labels with the patient's first and last name, patient file number (PF#) or medical record number (MR#), and 1 pink-top (EDTA) tube to the patient's bedside.
  2. Verify the patient's identity by asking the patient to state and spell his/her name, if able, while comparing the patient's identification band with the addressographed Crossmatch/Transfusion form and the patient's printed label.
  3. The patient's name and PF# or MR# must be obtained from the patient's identification wristband. If the patient does not have a wristband, a wristband must be obtained prior to drawing the patient's blood.
  4. Write the following data on the patient's printed or computer-generated gummed label at the bedside:
    • Date of phlebotomy
    • Time of phlebotomy
    • Legibly printed last name of phlebotomist
  5. Affix the patient's printed gummed label to the specimen tube at the patient's bedside.
  6. Send the labeled specimen tube with the Crossmatch/Transfusion form to the Blood Bank.

If the Blood Bank does not have a previous ABO/Rh on file for the patient, and the patient's initial blood type is other than type O, the Blood Bank will request a second sample to be collected for an ABO/Rh confirmation.

Failure to properly label the tubes will require that the specimens be redrawn. If the patient requires blood as an emergency and another sample cannot be drawn, an Emergency Release Form must be signed for uncrossmatched group O blood.

Specimens must be accompanied with a specimen transmittal or clinic encounter form that must match the specimen label. All handwritten requisitions accompanying specimens must have the following legible information:

  • Last, first, and middle name of patient
  • Medical record number (8 digits)
  • Patient’s date of birth
  • Last and first name of ordering physician
  • Nursing station or clinic originating requestTest(s) or procedure(s) requestedSpecimen source and body site
  • Date and time of specimen collection

All patient specimens MUST be placed in biohazard bags for transport to the Laboratory.

Laboratory procedures will not be performed on unacceptable specimens. Specimens collected using the incorrect tube type and transport material will not be tested. Specimens received showing evidence of leakage will not be tested. The nursing station from which the specimen originated will be notified.
Mislabeled Specimens

Specimens received unlabeled, double labeled, or with a requisition bearing a name and/or medical record number different than what is affixed to the specimen will not be tested. The patient’s nurse and/or physician will be notified to recollect the specimen.

  • Any specimen is unlabeled if the container holding the specimen (test tube, urine container, surgical specimen container, etc.) does not have the patient’s first and last name, medical record number, collection date and time, specimen type, and test required on it.
  • A specimen is mislabeled if it arrives in the laboratory with a requisition bearing different names on the requisition and the label OR if the name in the computer does not match the label. The laboratory will consider a mislabeled specimen an unlabeled specimen.
  • Blood Bank sample labels (crossmatch or type & hold) must be handwritten. Addressograph labels must not be placed on crossmatch specimens.

A specimen is incompletely labeled if some of the required information is missing:

  • If the name and the medical record number are missing, the specimen will be considered unlabeled and handled as such.
  • If there is any other information missing, the location where the specimen originated will be called to supply the information.

Specimens identified as precious specimens such as ascites fluid, amniotic fluid, cerebrospinal fluid, joint fluid, pleural fluid, surgical tissue/aspirate and certain timed specimens where the specimen cannot be recollected without undue harm to the patient will be tested only if the following conditions have been satisfied:

  • The patient’s physician must be notified. He/she must agree to accept responsibility for the specimen and give written authorization for testing.
  • In addition, the pathologist on call must be notified. He or she must review the circumstances and give written authorization for testing.A licensed caregiver designated by the patient’s physician must identify and correctly label the specimen.
  • It will be documented in the laboratory computer system that the test was performed on an unlabeled specimen so that this information appears on the preliminary and final reports.

The Blood Bank requires a new specimen for each unlabeled or mislabeled specimen, no exceptions.


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Watch the video: Προσδιορισμός ομάδων αίματος (December 2021).