Isolation and functional activity of human blood monocytes after adherence to plastic surfaces: comparison of different detachment methods.

The recovery and purity of monocytes were assessed after adherence of human blood mononuclear cells to plastic surfaces, with subsequent detachment after exposure to EDTA, lidocaine, trypsin or low temperature (4 degrees C). No differences in purity were observed (81-90%) but the recovery was highest after treatment with lidocaine and trypsin. Pretreatment of the plastic surface with fetal calf serum increased the recovery to approximately 60%. The chemotactic response of the manipulated monocytes was decreased when trypsin had been used, compared with monocytes detached after exposure to low temperature, lidocaine or EDTA. In conclusion, for the measurement of chemotaxis the best results are obtained with monocytes after lidocaine detachment from a serum-pretreated plastic surface.