Polymorphonuclear leukocyte phagocytosis: quantitation by a rapid radioactive method.

A rapid quantitative assay of phagocytosis has been developed. The method has been used to determine the phagocytic capability of human or dog polymorphonuclear leukocytes (PMN's) in a defined medium without added sera. The engulfment of 3H-labeled Staphylococcus albus is essentially complete in 30 minutes at 37 degrees C. Increase of phagocyte radioactivity is directly proportional to PMN per cubic centimeter over a wide range of cell concentrations. Maximal phagocytosis is observed at pH 7.5.