Application of flow cytometry and cell sorting to megakaryocytopoiesis

We have employed flow cytometry (FCM) and cell sorting to quantitate and study megakaryocytes in mouse and rat femoral marrow following their 20- to 30-fold concentration by centrifugal elutriation (CE). This enrichment of megakaryocytes permitted the first determination of their DNA-related fluorescence by FCM analysis following DNA staining. Fluorescence distributions of CE-enriched cell fractions following supravital staining with Hoechst 33342 were similar to those following chromomycin A3 staining of ethanol-fixed cells. Microscopic examination of cells sorted onto glass slides on the basis of their DNA-related fluorescence following supravital staining together with specific acetylcholinesterase staining for megakaryocytes indicated that megakaryocytes generally increased in cell size with increasing DNA content. This technologic application represents a significant advance in the study of megakaryocytopoiesis, since the kinetics of either the normal or perturbed population can now be studied rapidly and quantitatively.