Parameters affecting the adsorption of ligands to polyvinyl chloride plates in enzyme immunoassays

In the present work, we studied the efficacy of three blocking agents (HSA, BSA and OVA) in the inhibition of non-specific binding to PVC plates. According to the inhibition data, 1% OVA was the most effective blocking agent. On the other hand, the presence of detergents in all of the blocking solutions drastically decreased the percent inhibition of the non-specific binding. Furthermore, the effect of ligand concentration on adsorption and the kinetics of ligand adsorption to PVC plates were also investigated. Ligand adsorption is a linear function of input up to a limit (around 8.70 ng/mm2) where saturation is reached. The rate of adsorption of pure human IgG to PVC plates was proportionally increased with the temperature, as shown by proportional rate constants almost 2 times faster at 37 degrees C than at 4 degrees C. These results have practical implications for investigators using PVC for immunoassays and should be taken into consideration when designing such assays.