Optimal fixation of cells for use in solid-phase ELISA.

Glutaraldehyde (GA) is commonly used to achieve the stable fixation of whole cells onto microtitre plates for use in solid-phase ELISA. Concentrations of GA greater than 0.10% (v/v) were found to result in increased levels of non-specific binding of antibodies in ELISA. However, the use of 0.05-0.025% (v/v) GA permitted the stable fixation of cells whilst minimizing the non-specific effects seen with higher GA concentrations. The binding of cells onto microtitre plates was also found to be highly variable depending on both the type of plates and the nature of the cells being used.