Magakaryocyte quantitation.

A method is described for the quantitation of megakaryocytes. In this technic bone marrow sections obtained at the time of maximal marrow uptake of previously injected plasma bound (59)Fe are counted for radioactivity as well as the number of megakaryocytes and nucleated red cells. We calculated the total megakaryocytes by relating the ratio of megakaryocyte: radioactivity with the total marrow (59)Fe activity at the time of sampling. A multiple counting correction factor which is related to cell diameter and section thickness is required for quantitation of cell numbers from section material. The normal megakaryocyte number for the rat is 11.0 x 10(6)/kg, and 6.1 x 10(6)/kg for man.