Enzyme-linked immunosorbant assays (ELISAs) are widely used and validated for the detection and quantification of single analytes such as proteins, peptides, antibodies and hormones. The combination of the sensitivity of an enzyme assay with the specificity of antibodies provides a rapid, simple and highly sensitive method for the simultaneous quantification and analysis of the concentration of antigens or antibodies.
There are currently 3 major types of ELISA used by researchers:
Indirect ELISA typically used for screening antibodies
Competitive ELISA for antigen specificity
Sandwich ELISA for analysis of the amount of antigen present
PBL ELISA kits are heterogeneous antibody sandwich immunoassays. The antigen is captured by an antibody immobilized to the wells in a microtiter plate and a secondary antibody is used to complete the sandwich. The detection system which utilizes horseradish peroxidase (HRP) and Tetramethyl-benzidine (TMB) as the enzyme-substrate provides a sensitive and robust assay for the detection and quantification of interferons and cytokines.