CELLULAR-ACTIVITY OF MURINE PHAGOCYTES ISOLATED FROM PERIPHERAL-BLOODBY A DISCONTINUOUS GRADIENT

A mixture of Ficoll 400 and sodium diatrizoate (Hypaque) at a density of 1.077 g/ml has been used to isolate the mononuclear cells from the remaining haematic cells. A simple, inexpensive and classical method w as established to obtain substantially erythrocyte-free polymorphonucl ear cell preparations from mouse peripheral blood, using a mixture of the same substances but at a density of 1.119 g/ml. This method along with that at a density of 1.077 g/ml allows two cellular bands to appe ar which contain mononuclear and polymorphonuclear (PMN) cells, respec tively. Using this method, the counts of monocytes isolated from perip heral blood are significantly greater than those obtained by a one-ste p Ficoll-Hypaque procedure. On the contrary, the counts of PMN cells a re significantly smaller than when sedimentation in dextran (6% soluti on) is used after gradient centrifugation. In this paper, chemilumines cence assay has been used to analyze the possible variations in phagoc ytic activity of cells isolated by both procedures, since it appears t o be one of the most sensitive methods available for this purpose. The results obtained show a slightly greater activation in monocytes and PMN cells isolated by one-step Ficoll-Hypaque procedure, in comparison with another method which uses both Ficoll-Hypaque 1077 and Ficoll-Hy paque 1119, although statistical differences were not significant.