1. Blood Basics
Forensic Science

2. Are we sure it’s blood? If so, is it human? ... tests
What is it? ... components
Are we sure it’s blood? If so, is it human? ... tests
What does it do when it “travels”? … spatter

3. What makes up our blood? RBCs (Red Blood Cells) Why is your blood red?
How does its redness relate to its function?
Hemaglobin – a protein
Each RBC has ~ 280 million Hemaglobin proteins in it.
Each Hemaglobin protein has 4 iron (Fe) atoms in it.
Each iron atom binds to an O2 molecule… their purpose!

4. RED BLOOD CELLS RBCs

5. Why is your blood red? How does its redness relate to its function?
Cells Proteins Atoms bind to ___ …which is what these cells are for!
Important:
RBCs have no nucleus, so they contain no ______.

6. WHITE BLOOD CELLS (Leukocytes) – WBCs IMMUNE CELLS
What makes up our blood?
WHITE BLOOD CELLS (Leukocytes) – WBCs
IMMUNE CELLS

7. RED BLOOD CELLS (RBCs), with a lone WHITE BLOOD CELL (center)…
in the early stages of blood clotting.

8. What makes up our blood? PLASMA –
YELLOWISH LIQUID - nutrients and vitamins, hormones, clotting factors, and antibodies.
PLATELETS (Thrombocytes) –
coagulate (clot) your blood, when you have a wound

9. Platelets

10. UNIVERSAL DONORS: O type Rh – UNIVERSAL RECIPIENTS: AB type Rh +
What are blood types?
UNIVERSAL DONORS: O type Rh –
UNIVERSAL RECIPIENTS: AB type Rh +

11. How common is your blood type?
46.1%
38.8%
11.1%
3.9%

12. Are we sure it’s blood? If so, is it human? ... tests
Is it blood? Kastle-Meyer test
Uses Phenolthalein
Detects Hemoglobin
Pink if +

13. KASTLE-MEYER video clip

14. Luminol Is it blood? in a B I G area
Drawbacks !! Some metals, paints, cleaning products, and plant materials also react.
Can destroy DNA in blood.

15. Luminol can destroy evidence (DNA)

16. Crime Scene Analysis: Luminol in action

17. If it’s blood, is it HUMAN?
Is it HUMAN blood? HemaTrace test

18. Is it HUMAN?? Microscope Views
Bird Blood
Cat Blood
Dog Blood
Fish Blood
Frog Blood
Snake Blood
Human Blood
Horse Blood

19. Blood loss
A Class I Hemorrhage is usually considered 15%, or less, of an adult’s blood volume. In an 80 kg person this would be about 0.84 liters. At this level there are almost no signs or symptoms.
A Class II Hemorrhage is 15 to 30% loss of an adult’s blood volume. In an 80 kg person this would be about 1.68 liters. At this level the heart will start to beat faster, and the person will start to look pale, and feel cool. This is the beginning stages of shock.
A Class III Hemorrhage is 30 to 40% loss of blood. In an 80 kg person this would be about 2.24 liters. At this level the heart will be beating very fast, trying to keep up with the bodies needs. The person will look very pale, and start to be confused. This person is in shock, and in trouble. Fluids are needed very quickly in order to raise blood volume.
A Class IV Hemorrhage is greater than 40% and in an 80 kg adult this would be more than 2.24 liters. The body can no longer keep up with the blood loss and the person is in serious trouble.

21. What are the 4 components of blood
What are the 4 components of blood? Alternate with your partner to explain each one, starting with RBCs.

22. Blood reagent tests (screening tests) rely on the presence of what protein in the blood sample? What does the name of this protein say about it? Why might rust stains and blood stains appear similar? What does this protein do?

23. What is the quickest and most widely used screening test for blood
What is the quickest and most widely used screening test for blood? Explain how it works, and what reagents are used? What does a positive test look like?

24. How does luminol work? Are there any drawbacks to using luminol at a crime scene?

25. If the screening test on a piece of evidence is positive, which test is used to confirm that the blood is actually human?