Question

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)

Answer 1

2a. There is no antibody formation, so no agglutination takes place .

2b. It is the Antibody detection method in serum. It detects the presence and amount of antibodies within a person's blood. The amount and diversity of antibodies correlates to the strength of body's immune response.

It is performed by serially diluting the patient's plasma and testing with the appropriate RBCs to determine the highest titer where reaction can occur.

3. Procedures: i)WB buffers preparation, ii). Samples preparation, iii). Gel electrophoresis, iv). Protein transfer, v). Membrane blocking, vi). Antibody incubation, vii). WB detection and analyzing, viii). Data analysis.

Western blot is done to detect protein. Protenecious part of Nasty virus act as antigen.

Western blot analysis could detect target protein which is as low as 1ng due to high resolution of the gel electrophoresis and strong specificity and high sensitivity of the immunoassay.