A test for the evaluation of ingestion by neutrophils

A rapid, simple and inexpensive technique was developed to evaluate particle ingestion by neutrophils (PMNs) and alternatively investigate the activity of the complement system. Whole blood specimens, obtained in EDTA, were mixed with a suspension of activated Baker's yeast in minimal volumes (3 and 1 drops of each, respectively). The mixture was incubated at 37 degrees C for 1 h and centrifuged at 200 g for 5 min. The sediment was resuspended in FBS and blood films were stained with Giemsa. Two hundred PMNs/film were counted and the percentage of phagocytizing cells and the mean number of ingested particles per cell were determined. Samples from 11 male and 15 female subjects showed mean rates of 80.0 +/- 10.8 (SD) and 83.3 +/- 5.8 of PMNs with phagocytic vacuoles containing 2.9 +/- 0.5 and 3.2 +/- 0.7 ingested particles/cell, respectively. There were no statistically significant differences between sexes.