1. Serology
Forensics

2. Components of Blood
Plasma – fluid portion of blood (55%)
Cell (45%)

3. Plasma

4. Blood Cells Erythrocytes – Red blood cells
Carry oxygen through the body
Leukocytes – White blood cells
Cleans the blood of “foreign invaders”
Thrombocytes – Platelets
Responsible for blood clotting

5. Red Blood Cells

6. White Blood Cells

7. Platelets

8. Blood Clots

9. Serum
Liquid that separates from the blood when a clot is formed

10. Blood Questions to be answered: Is it blood? Is it human blood?
Whose is it?

11. Presumptive Tests for Blood
Kastle-Meyer color test - phenolphthalein and hydrogen peroxide are mixed together the blood’s hemoglobin will cause the formation of a deep pink color
Leucomalachite test - leucomalachite green mixed with acetic acid and distilled water; then a drop of sodium perborate will turn blood green and then darken.
Tetramethylbenzidine (TMB) – a possible blood stain is sampled with a moistened cotton swab and applied to a Hemastix containing TMB causing the strip to turn blue-green.

12. Presumptive Tests for Blood – Fluorescence
Luminol test - reaction with blood results in the production of light
Fluorescein – used to find stains that have been cleaned with chlorine bleach

13. Confirmatory Tests
Microcrystalline tests--add specific chemicals to the blood in order to form characteristic crystals
Work well with older stains
Takayama
Teichmann

14. Human vs Animal Blood Precipitin test blood is injected into a rabbit
anti-human antibodies are formed
precipitin line forms if sample is human blood

15. Blood Groups Can Give Blood To: Can Get Blood From Type Antigen
Antibody A A B
A, AB
O, A
B, AB
O , B B B A
Neither
A nor B AB
A and B AB
A, B, O, AB
Neither
A nor B O
A and B
A, B, O, AB O

16. Blood Type and Genetics
IA and IB are dominant over i
If there is a IA or IB, it will override the lower case “i”
Using a Punnett Square, you can determine what an offspring’s blood type could be.

17. The Genetics of Blood Type
Type A – IA IA or IA i
Type B – IB IB or IB i
Type AB – IA IB
Type O – i i

18. Rhesus or Rh Factor Also known as the D antigen
If the antigen is present, the blood is positive.
If the antigen isn’t present, the blood is negative.

19. Blood Reactions to Antiserum
Anti-A Serum
Anti-B Serum
BLOOD TYPE
Agglutination
No agglutination
No agglutination
Agglutination
Type A
Type B
Type AB
Type O

20. Population Distribution of Blood Types in the U. S.
Percent O 45 A 39 B 12 AB 4