Impact of bridge heterology on functional parameters of ELISA for 17 α-methyltestosterone

In this study, we have developed bridge heterologous ELISA for the detection of 17 α Methyl testosterone by incorporating aromatic spacers between 17α Methyl testosterone-3-Carboxymethyloxime and Horseradish peroxidase label through N-hydroxysuccinimide mediated carbodiimide reaction method. The immunogen 17α Methyl testosterone-3-Carboxymethyloxime-Bovine serum albumin used to generate the antibody was also prepared by the N-hydroxysuccinimide mediated carbodiimide reaction without using any spacer. We have studied the impact of bridge/aromatic spacers on functional parameters i.e. sensitivity, affinity and ED50 of the bridge heterologous assay and compared it with homologous assay. The five combinations of bridge heterologous assay using 17α Methyl testosterone-3-CMO-BSA antiserum and 17α MT-3-CMO-4,4'-Diaminodiphenyl sulphide-HRP, 17α MT-3-CMO-4,4'-Oxydianiline-HRP, 17α MT-3-CMO-Benzidine-HRP, 17α MT-3-CMO-p-Phenylenediamine-HRP and 17α MT-3-CMO-Dapson-HRP enzyme conjugates were evaluated. Out of these five combinations, the combination 17α MT-3-CMO-BSA with 17α MT-3-CMO-Benzidine-HRP showed the best results. Sensitivity, affinity and ED50 were improved and found to be 0.02 ng/mL, 0.086 × 10-8 L/mol and 2.95 ng/mL than homologous assay where Sensitivity, affinity and ED50 were 0.11 ng/mL, 0.02 × 10-8 L/mol and 5.78 ng/mL respectively. The cross-reactivity for this bridge heterologous assay combination was seen with only 4 steroids (6-hydrotestosterone- 6%, Tes...
Source: Journal of Immunological Methods - Category: Allergy & Immunology Authors: Source Type: research