Monocyte function in normal adults. Simplified methods of separation and testing

Human blood monocytes were separated by centrifugation over modified Ficoll-Hypaque and by this one-step procedure relatively high proportions (mean 54%) and yields of monocytes were obtained. Yields ranged from 0.22 x 10(9) to 0.98 x 10(9/l of blood and averaged 2 1/2 times the theoretical maximum yield calculated from the blood leucocyte and differential counts. A range of tests of monocyte function are described, namely, adhesion to glass, spreading on glass, chemotaxis under agarose and phagocytosis and killing of Candida albicans. These tests are generally simpler to perform than similar tests previously described and give very reproducible results which compare well with those reported by others. Normal values from 35 healthy Chinese adults are recorded.