[The distribution of peroxidase-positive granuloblastic precursors of normal human bone marrow separated in discontinuous albumin gradient density].

: Human normal marrow cells from 5 donors have been separated via discontinuous density gradient according to the Dicke's technique and the morphology of granulocytic cells recovered from density fractions has been examined; peroxidase negative myeloblasts are concentrated in low density fractions (specific density below 1.063), while granulated myeloblasts (peroxidase positive) are concentrated at densities ranging between 1.063 and 1.073; promyelocytes and myelocytes have been observed in all fractions although their maximal concentration is at density 1.073; metamyelocytes and polymorphonucleated cells are concentrated in the highest density fraction (density 1.078); some differentiated cells which are peroxidase negative have been observed; they concentrate at a density lower than that of peroxidase positive cells which look morphologically identical.