Figure 6

Mtb culture filtrate and Mtb cell extract titration in α-85 B direct and sandwich ELISA. A) various volumes of Mtb culture filtrate or B) different dilutions of Mtb cell extract were directly coated to the wells. After blocking antigen was detected using MFU50-C10-scFv-Fc-HRP at ~ 0.05 μg/mL and development with TMB. Sandwich ELISA: 100 ng of capture scFv-Fc MFU50-A10 were directly coated to the wells, after blocking A) various volumes of Mtb culture filtrate or B) different dilutions of Mtb cell extract were applied and incubated. Detection of bound antigen with MFU50-C10-scFv-Fc-HRP at ~0.05 μg/mL and development with TMB. Negative controls: BSA, M. smegmatis cell extract, M. vaccae cell extract all A450 = 0.05.