0. Chapter 8 Blood “Out damned spot! Out, I say
Here’s the smell of the blood still,
All the perfumed of Arabia will not
Sweeten this little hand. Oh, Oh, Oh!”
—William Shakespeare’s Lady Macbeth, in Macbeth
Kendall/HUnt

1. Chapter 10
Blood
You will learn:
That an antibody and an antigen of different types will agglutinate, or clump, when mixed together.
That the significance of the evidence depends on a characteristic’s relative occurrence in the population.
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2. Blood Determine whether a stain is blood.
Chapter 10
Blood
You will be able to:
Determine whether a stain is blood.
Determine whether a bloodstain is human or animal blood.
Determine the blood type of a simulated bloodstain using the ABO/Rh system.
Kendall/HUnt

3. Serology The examination and analysis of body fluids
Chapter 10
Serology
The examination and analysis of body fluids
From 1950’s to 1980’s -- high importance
With DNA -- now a matter of economics
Serology is the examination and analysis of body fluids. A forensic serologist may analyze a variety of body fluids including saliva, semen, urine, and blood. From 1950 to the late 1980’s, forensic serology was a most important part of lab procedures. With the development of DNA techniques, more time, money, and significance was placed in developing DNA labs. However, with limited funds and the time required for DNA testing, most labs still use many of the basic serology testing procedures.
Kendall/HUnt

4. Blood Characteristics
Chapter 10
Blood Characteristics
Plasma is the fluid portion of the blood (55%)
Cells (45%)
Erythrocytes are red blood cells. They are responsible for oxygen distribution.
Leukocytes are the white blood cells; they are responsible for “cleaning” the system of foreign invaders.
Platelets (proteins) are responsible for blood clotting
Serum is the liquid that separates from the blood when a clot is formed.
Kendall/HUnt

5. Chapter 10
Parts of Blood
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6. Unknown Stain at a Scene
Chapter 10
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
Kendall/HUnt

7. Presumptive Tests for Blood Determination
Chapter 10
Presumptive Tests for Blood Determination
Kastle-Meyer color test—a mixture of phenolphthalein and hydrogen peroxide; the hemoglobin will cause the formation of a deep pink color if blood is present
Hematest® tablet—reacts with the heme group in blood causing a blue-green color
Luminol test—reaction with blood to produce light
Kendall/HUnt

8. Chapter 10
Testing for Blood
Both the Kastle Meyer and Luminol test for presence of blood are examples of chemical reactions.
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9. Chapter 10
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10. Human vs Animal Blood Microscopic observation
Chapter 10
Human vs Animal Blood
Microscopic observation
Precipitin test—blood is injected into a rabbit; antibodies are formed; the rabbit’s blood is extracted as an antiserum; the antiserum is placed on sample blood. The sample will react with human proteins, if human blood is present. This test is very sensitive and requires only a small amount of blood.
Kendall/HUnt

11. Animal Blood Larger nucleic red blood cells Frog Blood Chapter 10
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12. Human Blood Red blood cells are most numerous; 5 to 6 million per mm3
Chapter 10
Human Blood
Red blood cells are most numerous; 5 to 6 million per mm3
White blood cells are larger and less numerous; 5 to 10,000 per mm3
Platelets are tiny, cellular fragments; 350 to 500,00 per mm3
Kendall/HUnt

13. Chapter 10
Secretors
80% of the population are secretors. Their blood-type antigens are found in high concentration in their body fluids such as saliva, semen, vaginal secretions and gastric juice.
Kendall/HUnt

14. Historical Perspective of Blood Typing
Chapter 10
Historical Perspective of Blood Typing
Karl Landsteiner
1900
4 types
In 1940 Rh factor
85% of Caucasions
94% Black Americans
99% Asians
Around 1900, Karl Landsteiner discovered that there are four different types of human blood based on the presence or absence of specific antigens found on the surface of the red blood cells.
In 1940, Landsteiner and Weiner reported the discovery of the Rh factor by studying the blood of the Rhesus monkey. 85% of Caucasians, 94% of Black Americans and 99% of all Asians are Rh positive.
Kendall/HUnt

15. How is our blood type determined?
Chapter 10
How is our blood type determined?
Your blood type is established before you are BORN, by specific GENES inherited from your parents.
You receive one gene from your MOTHER and one from your FATHER.
These two genes determine your blood type by causing proteins called AGGLUTINOGENS to exist on the surface of all of your red blood cells.
Kendall/HUnt

16. Chapter 10
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17. Chapter 10
Blood Typing
A-B-O and Rh systems are the most important in identifying blood
An individual that is type A has A antigens on his/her red blood cells
Type B has B antigens
Type AB has both A and B antigens
Type O has neither A nor B antigens
Kendall/HUnt

18. Chapter 10
Agglutination
For every antigen there is a specific antibody that will react with it to form clumps (agglutination)
For example, Red blood cells containing B antigens will react in the presence of B antibodies
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19. Chapter 10
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20. Chapter 10
What are blood types?
There are 3 alleles or genes for blood type: A, B, & O. Since we have 2 genes, there are 6 possible combinations.
Blood Types
AA or AO = Type A BB or BO = Type B OO = Type O AB = Type AB
45%
40%
11% 4%
How common are the 4 blood types?
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21. Blood Groups Type Antigen Antibody A A B A, AB O, A B, AB O , B B B A
Chapter 10
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
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22. Rh Factors A+ A- B+ B- AB+ AB- O+ O-
Chapter 10
Rh Factors
Scientists sometimes study Rhesus monkeys to learn more about the human anatomy because there are certain similarities between the two species. While studying Rhesus monkeys, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein.
The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor.
If your blood does contain the protein, your blood is said to be Rh positive (Rh+). If your blood does not contain the protein, your blood is said to be Rh negative (Rh-).
A+ A- B+ B- AB+ AB- O+ O-
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23. Rh factor Determined by presence of another antigen
Chapter 10
Rh factor
Determined by presence of another antigen
People having antigen are Rh +
People not having are Rh-
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24. Use the results shown to determine the blood type for each sample.
Chapter 10
Blood Typing
Use the results shown to determine the blood type for each sample.
- = No Clumps
+ = Clump A B Rh
Blood Type: ___
To determine a person’s blood type, we add three different serums to blood samples and see if clumps form.
Clumps = Positive (+) No Clumps = Negative (-) What would the blood type be for this sample?
Kendall/HUnt

25. - = absent + = present Blood Typing
Chapter 10 A B Rh
Blood Type: ___ A B Rh
Blood Type: ___
Blood Typing
Use the results shown to determine the blood type for each sample. A B Rh
Blood Type: ___ A B Rh
Blood Type: ___ A B Rh
Blood Type: ___
- = absent
+ = present
Kendall/HUnt