Chemiluminescent labelled streptavidin (STAV) as a universal marker in steroid and peptide immunoassays

✍ Scribed by Strasburger, C. J. ;Kohen, F.

• Publisher: John Wiley and Sons
• Year: 1989
• Weight: 543 KB
• Volume: 4
• Category: Article
• ISSN: 0884-3996
• DOI: 10.1002/bio.1170040117

✦ Synopsis

The tetrameric structure of streptavidin and its exceptionally strong affinity t o biotin (K, = IOl5M-') can be exploited t o achieve an amplification of the signal in immunoassays. In the approach described here streptavidin (STAV) labelled with aminobutylethyl-isoluminol (ABEI) served as a universal marker in immunoassays for both haptens and big antigens. The advantageous features of streptavidin can be applied t o any immunoassay using biotinylated antibodies as the primary probe.

In two-site immunometric assays for larger antigens the liquid phase 'tracer' antibody is biotinylated. In hapten assays the solid phase antigen technique (Wood et a/., 1982) is employed, in which sample-antigen and solid phase-antigen compete for a biotinylated antibody. In this paper w e demonstrate the use of STAV-ABEI as a universal chemiluminescent label in steroid assays and in an immunometric assay using human growth hormone (hGH) as an example.