1. Intro to Blood and Blood Types

2. Important Vocab: Fill in vocab table from notes for homework!
Antigen
Plasma
Red blood cells
White blood cells
Antibodies
Agglutination

3. Unknown Stain at a Scene
Questions to be answered:
Is it blood?
Is it human blood?
Whose is it?
Determine blood type, alcohol content, drugs present
Determine the method(s) in which blood may have been deposited
We’re going to do this first :) 3

4. Blood Facts! Average adult has about 5 liters of blood
Carries oxygen, nutrients, carbon dioxide and other wastes
Fights infections
Made up of 4 things:
Red blood cells (RBCs)
White blood cells (WBCs)
Platelets
Plasma

5. Composition of Blood 5

6. What can each part tell us?
Plasma
Liquid part of blood
Carries nutrients, waste products, hormones, and many other things.
What do you think forensic scientists can determine from studying the plasma? 6

7. What can each part tell us?
2. White blood cells
Fight off diseases and foreign substances.
Only blood cells with a nucleus.
What do you think forensic scientists can determine from studying the WBCs? 7

8. What can each part tell us?
3. Red blood cells
Carries gasses like oxygen and carbon dioxide through the body.
Do not have a nucleus.
What do you think forensic scientists can determine from studying the RBCs? 8

9. Red Blood Cells Determine Blood Type
Antigen – a protein that can cause the body to make antibodies.
Antigens found in the membrane of red blood cells account for blood types.
There are 2 sets of antigens on the RBCs: ABO antigen and Rh antigen. 9

10. A and B Antigens The blood antigens come in two “flavors” A and B
Based on your genes, you can have 1 of 4 types:
1. Just A antigen = A type
2. Just B antigen = B type
3. Both A and B antigens = AB type
4. Neither A or B antigens =O type. 10

11. RH Factor
Did you ever wonder why some people have “+” blood and others have “-” blood?
A+ A- B+ B- AB+ AB- O+ O- 11

12. RH Factor
85% of the human population has a second antigen called Rh factor on their red blood cells.
Found from studying Rhesus monkey.
Have it = “Rh positive” Don’t = “Rh Negative”
A+ A- B+ B- AB+ AB- O+ O- 12

14. Practice Naming the Blood Types

15. Practice Naming the Blood Types

16. Practice Naming the Blood TypesRh B Rh Rh B B Rh Rh Rh B Rh B

17. Practice Naming the Blood TypesRh Rh Rh Rh Rh Rh Rh

18. Complete the First 2 Columns of the Blood Types Chart!
Draw the RBC
Antigens Present
Reaction with A antibody
Reaction with B antibody
Reaction with Rh antibody A-

19. How Do We Determine Blood Types?
Antibody – reacts with an antigen
Every antibody reacts with only 1 antigen
We can use it to identify antigens

20. How Do We Determine Blood Types?
Everyone makes antibodies against blood antigens
Only make them for antigens you do not have.
If a person has A antigen on their RBCs, will they make A antibody? 20

21. How Do We Determine Blood Types?
Agglutination- blood cells clump when an antibody recognizes the antigen.
Because we can see this happening, we can figure out what antigens are present.

22. Practice Predicting Agglutination

23. Practice Predicting AgglutinationB A B A A B B A A A B A B

24. Practice Predicting AgglutinationB Rh B Rh Rh B B Rh Rh Rh B Rh B

25. Practice Predicting AgglutinationRh Rh Rh Rh Rh Rh Rh

26. Complete the Last 3 Columns of the Blood Types Chart!
Draw the RBC
Antigens Present
Reaction with A antibody
Reaction with B antibody
Reaction with Rh antibody A-