Objective
This project has two objectives:
Introduction
The human immune system has various ways of responding to an infection caused by bacteria or viruses. Our bodies produce proteins (antibodies) that are highly specific for the infectious agent as a part of our "humoral" immune response. The antibodies help stop the infection from spreading further and help to eliminate the bacteria or virus from the body.
Antibodies are also used to help our bodies find and destroy "foreign" cells such as tumors. Because antibodies bind tightly to only one type of structure on the surface of cells (antigen), they can also be useful for identifying different types of blood cells. It is important to correctly identify blood cells in our bodies if we ever need to receive blood from someone else because we are sick (transfusion).
Our blood type is determined based on the presence or absence of two proteins on the surface of our red blood cells (Type A and Type B). There are four possible combinations of blood types namely: Type A, Type B, Type AB, and Type O (contains neither A nor B proteins). This is referred to as the ABO blood type. In addition, red blood cells have a Rhesus factor or Rh, which is either present or absent. If the Rh factor is present, the cells are referred to as Rh positive. Including both the ABO and Rh systems for blood typing, there are a total of 8 possible blood types that are shown in Table 1. The table also shows approximately what percentage of the U.S. population is each blood type.
| Blood Type | % of U.S. Population |
|---|---|
| O positive | 38 |
| A positive | 34 |
| B positive | 9 |
| O negative | 7 |
| A negative | 6 |
| AB positive | 3 |
| B negative | 2 |
| AB negative | 1 |
Blood types are determined by using antibody reagents that specifically react with the A, B, and Rh proteins on the surface of red blood cells. First, three drops of blood are placed on a microscope slide. Next, a drop of anti-A reagent is added to one drop of blood, a drop of anti-B reagent is added to the second drop of blood and a drop of anti-Rh reagent is added to the third drop of blood. The slide is gently rotated and examined for clumping (agglutination). If clumps are seen in the anti-B and anti-Rh reagents, then the person's blood is considered "B positive."
When you donate blood, your blood type is determined (usually by the American Red Cross) and is used to match your blood with someone who needs it. If someone got the wrong blood type during a transfusion, they could have a very severe reaction. Type O negative blood is considered the "universal donor" because anyone can receive that blood type without having a reaction. Type AB positive is considered the "universal recipient" because someone with that blood type can receive blood from anyone else without having a reaction.
Terms, Concepts and Questions to Start Background Research
In order to do this project, you should conduct background research that enables you to understand the following terms and concepts:
Bibliography
Materials and Equipment
This project uses Carolina Biological Supply Company kit #70-0101 ($24.95). It can be purchased from:
Carolina Biological Supply Company
2700 York Road
Burlington, NC 27215
800-334-5551
Fax: 800-222-7112
www.carolina.com
Experimental Procedure
| Agglutination Reaction? | |||
| Blood type | Anti-A | Anti-B | Anti-Rh |
| A+ | Yes | No | Yes |
| A− | Yes | No | No |
| B+ | No | Yes | Yes |
| B− | No | Yes | No |
| AB+ | Yes | Yes | Yes |
| AB− | Yes | Yes | No |
| O+ | No | No | Yes |
| O− | No | No | No |
Variations
Credits
Author: Mark A. Schenerman, Ph.D. (MedImmune)
Last edit date: 2008-08-10 22:00:00
If you like this project, you might want to think about career opportunities in
Biotechnology.
Growing, aging, digesting—all of these are examples of chemical processes performed by living organisms. Biochemists study how these types of chemical actions happen in cells and tissues, and monitor what effects new substances, like food additives and medicines, have on living organisms. Learn more about this career: Biochemist.
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