lecture 13

Question 1

Indirect ELISA

Answer 1

Detects antibodies in patient sera based on binding to a known antigen
Known antigen is adsorbed to the surface of a well and mixed with unknown antibody
If an Ag-Ab complex forms, an added indicator antibody will bind and produce a color change
Common test used for antibody screening for HIV
Because false positives can occur, a verification test with other methods may be necessary

Question 2

Direct ELISA

Answer 2

Detects antigens based on binding to a known antibody
Known antibody is adsorbed to the bottom of a well and incubated with an unknown antigen
If an Ag-Ab complex forms, it will attract the indicator antibody and color will develop in these wells

Question 3

Enzyme-Linked Immunosorbent Assay (ELISA)

Answer 3

Uses an enzyme-linked indicator antibody to visualize Ag-Ab reactions
Relies on a solid support such as a microtiter plate that can adsorb the reactions

Question 4

Secondary antibodies

Answer 4

bind to the primary antibody to assist in detection, sorting and purification of target antigens. To enable detection, the secondary antibody must have specificity for the antibody species and isotype of the primary antibody being used and generally is conjugated.