20. Adaptive Immunity

______ ELISA has basically replaced immunoblotting.

Which term describes antibodies binding to a virus preventing it from attaching to host cells?

The study of antigen-antibody reactions is referred to as _____.

Which of the following is NOT a protective outcome of antibody-antigen binding?

Label components of the direct and indirect ELISA tests in the following situations. Which test is direct? Which test provides definitive proof of disease?

How does the antigen in an agglutination reaction differ from that in a precipitation reaction?

Put the following in the correct sequence to elicit an antibody response:

(1) TH cell produces cytokines

(2) B cell contacts antigen

(3) antigen fragment goes to surface of the B cell

(4) TH recognizes antigen fragment and MHC

(5) B cell proliferates.

a. 1, 2, 3, 4, 5

b. 5, 4, 3, 2, 1

c. 3, 4, 5, 1, 2

d. 2, 3, 4, 1, 5

e. 4, 5, 3, 1, 2

Explain the effects of excess antigen and antibody on the precipitation reaction. How is the precipitin ring test different from an immunodiffusion test?

Match the following serological tests in column A to the descriptions in column B.

Match each of the following tests in column A to its positive reaction in column B.

The examples in questions 1 and 2 are:

a. Direct tests

b. Indirect tests

Use the following choices to answer questions 4 and 5:

a. Anti-Brucella

b. Brucella

c. Substrate for the enzyme

Which is the third step in a direct ELISA test?

A purified protein from Mycobacterium tuberculosis is injected into a person’s skin. A hardened, red area develops around the injection site within 3 days.

Use the following choices to answer questions 4 and 5:

a. Anti-Brucella

b. Brucella

c. Substrate for the enzyme

Which item is from the patient in an indirect ELISA test?

In an immunodiffusion test, a strip of filter paper containing diphtheria antitoxin is placed on a solid culture medium. Then bacteria are streaked perpendicular to the filter paper. If the bacteria are toxigenic,

a. The filter paper will turn red

b. A line of antigen–antibody precipitate will form

c. The cells will lyse

d. The cells will fluoresce

e. None of the above