Question

A direct ELISA ________.

A. detects the presence of a pathogen in the patient by looking for the presence of patient-derived antibodies against that pathogen
B. involves coating the plate with a known antigen first
C. involves coating the plate with a known antibody first to detect protein of the pathogen in the patient
D. A and B

14. Which of the following is an example of directed evolution?

A. Protoplast fusion
B. UV irradiation
C. Site-directed mutagenesis
D. All of the Above

14. Which of the following is an example of directed evolution?

A. Protoplast fusion
B. UV irradiation
C. Site-directed mutagenesis
D. All of the Above

Answer 1

1. Direct ELISA test is the simplest type of ELISA where antigen is adsorbed to a plastic plate, then an excess of another protein (bovine serum albumin) is added to block all the other binding sites. While an enzyme is linked to an antibody in a separate reaction, the enzyme-antibody complex is applied to adsorb to the antigen. After excess enzyme-antibody complex is washed off, enzyme-antibody bound to antigen is left. By adding the substrate, the enzyme is detected by the formation of a coloured product. So the answer is option both A and B.

14. The answer is all the above. Directed Evolution is used to describe various molecular biology techniques that mimic natural selection and are extremely useful for protein engineering. Such techniques include chemical mutagenesis, error-prone PCR, incremental truncation, and gene shuffling, UV irradiation, protoplast fusion to name but a few.