Flow cytometry of mouse bone marrow cells cultured in vivo or in vitro.

We have developed new methods for counting cyto-(fluoro)-metrically cells retrieved from diffusion chamber and methylcellulose cultures of mouse bone marrow. Total cell counting and DNA distribution measurements were based on detection of the fluorescence from propidium iodide stained nuclei. Staining of cell nuclei with propidium iodide further allowed the separate enumeration of avid phagocytes that had endocytosed fluorescent latex beads. Finally, we quantified peroxidase positive cells by using o-Dianisidine as a substrate for the enzyme, the formation of brown reaction product being enhanced by the presence of lidocaine and dichlorophenol. We found the new techniques precise, reliable and suitable for analysis of cell growth and maturation in culture.