Mixtures of D2 and B6 marrow maintain the parental ratio of LTC-IC in culture.

Bone marrow cells from D2, B6, and a 1:1 mixture of the marrows were plated onto S17 stroma. Between 48 and 192 wells were seeded for each cell concentration. The data depicted are from 2 independent experiments, a dashed vertical line separates different experiments. LTC-IC values (per 10⁵ cells seeded) at 4 weeks of culture are indicated above the figure. Positive wells were then harvested and the cells from each well were stained with mAb specific for H2^d (D2, white bars) and H2^b (B6, black bars). Because the cells in each microculture were derived from an LTC-IC, the genotype of the differentiated progeny establishes the genotype of the LTC-IC. The plating density (cells/well), percentage negative wells, and number of wells tested for each cell dilution (n) is indicated below the figure.