Summary of ELISA Protocols丨Zoonbio

ELISA protocol	Uses	Required reagents	Comments
Indirect	Antibody screening;epitope mapping	Antigen, pure or semipure: test solutioncontaining antibody;enzyme conjugate that binds Ig of immunized species	Does not require the use of preexisting specific antibodies;requires relatively large amounts of antigen
Direct competitive	Antigen screening;detect soluble antigen	Antigen, pure or semipure; test solution containing antigen;enzyme-antibody conjugate specific for antigen	Rapid assay with only two steps;excellent for measuring antigenic cross-reactivity
Antibody-sandwich	Antigen screening;detect soluble antigen	Capture antibody (purified or semi-purified specific antibody); test solution containing antigen; enzymeantibody conjugate specific for antigen	Most sensitive antigen assay;requires relatively large amounts of pure or semi-pure specific antibody (capture antibody)
Double antibody–sandwich	Antibody-screening;epitope mapping	Capture antibody:(specific for Ig of immunized species);test solution containing antigen; enzymeantibody conjugate specific for antigen	Does not require purified antigen;relatively long assay with five steps
Direct cellular	Screen cells for expression of antigen; measure cellular antigen expression	Cells that express antigen of interest;enzyme-antibody conjugate specific for cellular antigen	Sensitive assay for bulk screening;insensitive to heterogeneity of expression in mixed population of cells
Indirect cellular	Screen for antibodies against cellular antigens	Cells used for immunizing; test solution containing antibodies; enzyme conjugate that binds Ig of immunized species	May not detect antibodies specific for cellular antigens expressed at a low density