Immunoscreening of gt11 Expression Libraries Using an Avidin-Biotin Detection System

Although the avidin-biotin detection system has been used for immunochemical staining of tissues for some time, its use for amplification in immunoassays was not described until 1979 (1 ). The biological basis for the system is the very tight binding of four molecules of biotin to one of avidin. This has an amplification ability that can be used to increase the sensitivity of detection of antibodies or other biotin-labeled molecules. Using antibodies raised to a purified peptide and an efficient expression system, such as λgtll (2 ), the clone(s) containing the cDNA for that peptide can usually be identified by detection of expressed antigens.