Comparison of agar and methylcellulose culture methods for human erythroid colony formation.

An agar culture method to permit human erythroid colony growth was described and was compared with the standard methylcellulose culture method. Although the cloning efficiency was greater and the colonies were larger in size in methylcellulose, the relative number of colonies was indistinguishable in the two culture systems after short-term exposure to cytosine arabinoside, adriamycin, tritiated thymidine, or busulfan. Thus, the agar culture system permits the growth of erythroid progenitor cells, which are at the same stage of differentiation as erythroid progenitor cells which can grow in methylcellulose. Since cultures in which agar is used as the semisolid matrix can be fixed and counted at the convenience of the investigator, the cloning of erythroid progenitor cells in agar will greatly facilitate investigation of the proliferative properties and drug sensitivity of erythroid progenitor cells obtained from normal individuals as well as from patients with hematologic neoplasms.