Blood Typing

Your next instruction is to dispose of the toothpick. You will use a new toothpick to stir each sample. Why is this important?

Using the same toothpick would cross-contaminate the samples. Correct. Each blood sample needs to be mixed with only one type of antibody. Using the same toothpick will contaminate the samples.

• If you have blood type B, you will have

anti-A antibodies.

• If you have blood type A, you will have

anti-B antibodies.

The blood plasma may also contain

antibodies, depending on the ABO and Rh blood types.

Blood types are determined by the

antigens that are present on the surface of red blood cells (RBCS, also known as erythrocytes).

• If you have blood type AB, you will NOT have

any anti-A nor anti-B antibodies.

If you have blood type 0, you will have

both anti-A antibodies and anti-B antibodies.

• ABO blood type is determined

by the presence of A, B, both (AB), or neither (0) of the A or B antigens.

Type O can potentially donate to

everyone because their blood has no antigen to attack. However, Type O should first have its own anti-A and anti-B antibodies removed.

Red blood cell membranes contain

glycoproteins and glycolipids that determine your ABO blood type and proteins that determine your Rh (+/-) blood type.

• Rh blood type is determined by

the presence of (+) or lack of (-) the D antigen.

Agglutination

The clumping of cell bound antigens, as occurs when antibodies attach to ABO and D (Rh) antigens.

Type AB cannot donate to

Type A because they have anti-B antibodies or Type B because they have anti-A antibodies.

Type B cannot donate to

Type A or Type O because they both have anti-B antibodies.

Type A cannot donate to

Type B or Type O because they both have anti-A antibodies.

Which blood samples show agglutination?

A. Anti-A

Blood can only be donated from a person with a specific

ABO antigen to a person without antibodies for that antigen.

Antibody

An immune system protein that is found in most body fluids, especially blood plasma. Antibodies bind to antigens to aid the immune response.

Antigen

Any substance that is capable of causing an immune reaction. These are usually proteins, glycoproteins, or glycolipids.

Which blood samples show agglutination?

B. Anti-B

What do you label on the microscope slide?

Blood sample number and Serum type

Which blood samples show agglutination?

C. Anti-D

Negative

Does NOT mean "bad." In testing, negative means what you are testing for is absent.

Positive

Does NOT mean "good." In testing, positive means what you are testing for is present.

Serum/Sera

Fluid containing antibodies.

• No one has anti-D (Rh) antibodies unless they are

Rh- AND have been previously exposed to Rh+ blood.

• Rh+ blood should not be transfused to an

Rh- person; however, Rh- blood can be donated to an Rh+ person.

Agglutinogen

The substance being clumped in an agglutination reaction. Antigens in blood typing are agglutinogens.

Agglutinin

The substance causing clumping in an agglutination process. Antibodies in blood typing are agglutinins.