Homologous ELISA for detection of prednisolone in human serum

An enzyme-linked immunosorbent assay to measure prednisolone have been developed. An antibody was raised in rabbits using prednisolone-21-hemisuccinate (PSL-21-HS) conjugated to bovine serum albumin. Similarly, PSL-21-HS was conjugated to horseradish peroxidase to prepare enzyme conjugate. The developed assay has been validated for sensitivity and effective displacement at 50% of the assay were 0.078 and 2.64ng/mL, respectively. This assay showed cross-reaction with only 4 steroids - i.e. progesterone 1.76%, 17-OH progesterone 5.89%, cortisol 7.69% and prednisone 1.13%, out of 55 analogous steroids. The percent recovery of prednisolone from the exogenously spiked human serum pools was in the range of 94.84-100.17%. The intra-assay and inter-assay coefficients of variation ranged from 5.79% to 8.00% and from 3.23% to 8.63%, respectively. The serum prednisolone values obtained by this method correlated well with the commercially available kit and found to be 0.93.