1. Types of Blood

2. Karl Landsteiner (Austrian Biologist)
1901 recognized all human blood was not the same
Came up with ABO classification of blood
Important because of so many blood transfusions going bad
Also discovered the RH factor (rhesus factor)

3. Leon Lattes 1916 showed the value the ABO classification of blood
Wife thought he was cheating while he was away because of blood on his shirt, he confirmed through tests they were the same blood type
First checked if it was human blood etc
Helped others solve cases
Tests for ABO antibodies in bloodstains are called Lattes Test

4. Blood Factors
A specific combination of antigens, enzymes, and proteins in the blood.
Antigens are found on RBC (Red blood cells)
Four Types of Blood A,B, AB, & O.
Type A- has A antigen
Type B- has B antigen
Type AB- has both AB antigen
Type 0 – has NO antigen
NO TWO PEOPLE HAVE THE SAME PROTEIN FACTORS

5. Chart to help with Blood Types

6. Why are types so important?
Lets say you have A blood. Your body has made antibodies for type B blood. This way if your body comes into contact with B blood or AB blood it will destroy the blood cells needed.
Also, it can cause AGGLUTINATION – clumping of the RBCs
Before 1901, scientists were unaware of this, so transfusions did not go over well.

7. Rh Factor Rhesus Factor Referred to as “D” antigen
People who have this antigen are known as RH +, those without RH-
Most of population 85% are RH +

8. Why would this be important for FORENSICS?
DNA analysis is GREAT, but extremely time consuming & expensive
ABO & RH factor classification can be done in many situations
Whole blood & Dry blood stains
Can show two samples have different origins
Can also be done QUICKLY & without a lot of expense.
80% of people are SECRETORS
Secretor- people whose blood type antigens are also found in other body fluids

9. Review
Who first discovered the ABO classification system? Why was this so important?
What was important about Leon Lattes?
Which type of blood cells have antigens? And What are the four types?
Explain how the four blood types work. Who can receive while who can donate?
What is the RH Factor?
Why is this important for Forensics?