Small-scale isolation and characterisation of human peripheral blood monocytes

A technique is described for the isolation and characterisation of monocytes from 15 ml of human peripheral blood. After density gradient centrifugation over Ficoll-Hypaque, monocytes are purified further by substrate adherence under carefully defined conditions. The use of a simple microwell slide system permits the production of multiple small-scale monolayer populations which can be characterised further in terms of their histochemical reactivity (combined stain for chloroacetate and non-specific esterases); endocytic capacity (latex particles); Fc (sensitised ox erythrocytes) and C3 (serum-coated yeast) receptor expression; and precursor maturation potential (7-day cultures). Evidence of considerable cellular heterogeneity is presented.