A cytospin of pooled marrow from mice transplanted with 10,000 Rh/Hoe^dull cells and resorted for cells with the same Rh/Hoe^dull characteristics of the cells initially seeded. (A) Cells are stained using in situ hybridization for a digoxigenin-conjugated Y chromosome-specific “painting” probe and visualized with rhodamine using a 590-nm longpass filter. Positive cell (d) is of donor origin, while unlabeled cells (h) are of host origin. (B) Same as (A) except counterstained with DAPI, excited with UV, and visualized using a 450-nm longpass filter. Original magnification (OM) × 313.