Serial Dilutions / Paired Antibody Titers

Assignment - Session 6

1. Using the diagram below, answer the questions labeled a, b, and c. Antibody is in the center well and antigens are in the wells numbered 1, 2, 3, and 4.

2

1 3

4

a. What is the relationship between the antigen in well 2 and the antigen in well 3?

b. What is the relationship between the antigen in well 3 and the antigen in well 4?

c. What is the relationship between the antigen in well 1 and the

antigen in well 4?

2. A serial dilution of patient serum is done:

Tube #1 Tube #2 Tube #3 Tube #4 Tube #5 Tube #6

1:2 1:4 1:8 1:16 1:32 1:64

One milliliter of RBCs is added to each tube and the following is noted:

Tube #1 No agglutination

Tube #2 No agglutination

Tube #3 Agglutination

Tube #4 Agglutination

Tube #5 Agglutination

Tube #6 Agglutination

a. What has happened in Tubes #1 and 2?

b. What is the antibody titer? 3. You suspect that an individual has been infected with the Nasty Virus, a

highly contagious virus that has been reported in your city. Describe how you could use the Western blot procedure to confirm that this individual has been infected. (Please list the steps of the Western Blot procedure)