Fig. 4

Leishmania 40S ribosomal protein S12 antigen (1357) sandwich ELISA had the highest sensitivity and strongest signal among the sandwich ELISAs prepared from the eight rabbit antisera. Unlabeled capture IgG and biotinylated detection IgG were prepared from each of the rabbit sera and tested in sandwich ELISAs. The capture IgG was used at a 1:2000 dilution. Whole cell lysates of 100 to 1 million L. donovani promastigotes were added to the wells of the 96-well ELISA plate. Captured antigen was detected with the homologous biotinylated IgG, Avidin-HRP, and TMB substrate, and absorbance measured at 450 nm