A comparison of three reverse haemolytic plaque assays.

One fluid phase and two solid phase reverse haemolytic plaque (RHP) assays were used to quantitate plaque forming cells (PFC) in pokeweed mitogen (PWM) stimulated and unstimulated cultures of mononuclear cells (MNC) from 18 normal donors. There was a close correlation between the results of the three assays and between each one and the number of cells containing cytoplasmic Ig (cIg). All three correctly identified donors with a low PWM response. The fluid phase assay was the most sensitive with PFC values in PWM stimulated cultures two to four times higher than with the solid phase assays.