Avidin and streptavidin in clinical diagnostics.

With the introduction of the SA/Bi technology into the clinical diagnostic field ultrasensitive tests with an acceptable turn-around time became feasible. Cytokine ELISAs with lower detection limit in the picogram range became finally available. Prior to the introduction of SA/Bi only elevated levels of target could be detected by short time tests but not the normal base level. The turn around time for standard clinical immunological tests was reduced to 10-20 min from 2-4 h in old assays.