38.4 Direct ELISA
In direct ELISA, the antigen is immobilized on the microwell plate. Then an
enzyme-labelled primary antibody is added to the well that reacts directly with
antigen. Direct detection ELISA is not a frequently used method but is used
commonly for immunohistochemical staining of tissues and cells.
38.5 Applications of ELISA
Enzyme-linked immunosorbent assay is an important tool tofind the presence of
antigen or antibody in a sample. It is used commonly to assay various proteins
including insulin, luteinizing hormone, etc. Indirect ELISA is used for diagnosis of
human immunodeficiency virus. It can also be used for the screening of monoclonal
antibodies. The most commonly used pregnancy test is based on ELISA which
detects human chorionic gonadotropin in urine. It is also being used in food industry
for detection of potential food allergens.
38.5 Applications of ELISA 155