[Immunofluorescence with incident light in syphilis serology. FTA-5-1 and FTA-ABS-1 reactions]

The FTA-5 and FTA-ABS reactions have been comparatively evaluated on human sera by two microscopic systems in incident and transmitted light. The results demonstrate that the sensitivity of the reactions is increased by employing the incident light microscopic system. Furthermore they demonstrate the opportunity of performing both reactions FTA-5-I and FTA-ABS-I on each serum in order to distinguish type-specific and genus-specific antibodies present in luetic sera.