A microassay for leukocyte migration: analysis of its reproducibility

A reliable microassay for human leukocyte migration is described by which 50 to 100 assays can be performed each day in quadruplicate with the number of indicator cells obtainable from 10 to 20 ml of peripheral blood. The reproducibility of this method is demonstrated with respect to the variability among replicate test wells (including reading), the variability among different test readers, the variability among replicate cultures, and the variability of using indicator cells from different subjects. A microculture system is described that requires only 75,000 mononuclear cells to consistently produce detectable polymorphonuclear leukocyte migration inhibition factor in response to PPD. The reproducibility of this culture system is demonstrated with respect to the variability of lymphocyte responsiveness on repetitive testing in the same individuals.