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Old 07-20-2016
PowerDan PowerDan is offline
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Quote:
Originally Posted by nakeya52 View Post
Can anyone answer the C psittaci question?

An investigator develops an indirect immunofluoresoent immunoassay for detecting C psittaci in respiratory secretions. Polyclonal antisera and
monoclonal antibody are generated against a single killed strain of C. psittaci. An initial enzyme immunoassay with the immunogenic strain shows comparable results with the polyclonal antisera or the monoclonal antibody.

In a clinical setting, however, it is found that the polydonal antisera are substantially more sensitive than the monoclonal antibody for detecting C. psittaca‘ infection. Which of the following best explains this difference in sensitivity?


A) The affinity of the monoclonal antibody for its complementary epitope is lower than that of the polyclonal antisera

B) The avidity of the monoclonal antibody for its complementary epitope is lower than that of the polyclonal antisera

C) The fluorescein isothiocyanate label does not bind as tightly to the monoclonal antibody as It does to the polyclonal antisera

D) The greater diversity of epitopes recognized by the polyclonal antisera permits identification of strains not recognized by the monoclonal antibody

E) The monoclonal antibody lacks portions of the Fc region critical for recognition by anti-lgG antibodies in this indirect assay
Option (D).
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