Bioluminescent enzyme immunoassay with biotinylated firefly luciferase

A sensitive bioluminescent enzyme immunoassay (BLEIEA) has been developed u sing biotinylated firefly luciferase, The streptavidin-biotin based BLEIAs were applied to measuring human chorionic gonadotropin (hCG),human growth h ormone (hGH), and staphylococcal protein A (SPA). The measurable ranges of hCG, hGH, and SPA were 0.013 to 20 mIU/mL, 0.056 to 30 ng/mL, and 0.001 to 1 ng/mL, respectively. The measurable range of Staphylococcus aureus Cowan I was 10(3) to 10(5) colony forming units/mL (cfu/mL) using the SPA assay s ystem. The proposed streptavidin-biotinylated luciferase system was shown t o be applicable to several sandwich type enzyme immunoassays with high sens itivity. Furthermore, we investigated simultaneous detection of two substan ces in immunoblotting using two biotinylated luciferases with different col ored light emissions.