The normal healthy human blood was heparinized with one-tenth volume of 0.1 per cent heparin solution. Ten thousand units of penicillin and 10 mg of streptomycin were added to each 100 ml of the blood. The whole blood was distributed into culture tubes in amounts of 0.5 ml or 1.0 ml.
The tubes were rubber-stoppered, inclined at 4045 degrees against the level, and iucubated in static state at 37°C. A few days after incubation, the plasma and free blood cells in tubes were discarded and washed with PBS twice. Then fresh culture medium was placed into the tubes to maintain a number of cells remained adhered on the wall.