PCR analysis of DJ_H and VDJ_H gene rearrangements on DNA from different cell subsets. BLIN1, a pre–B-cell line that had completely rearranged VDJ_H, and CD34^–CD19⁺ cells sorted from fresh cord blood were used as controls. Purified CD34⁺CD10^–CD19^– cord blood cells sorted at day 0 to initiate the cultures, CD79a⁺-enriched CDw127⁺CD11b^–CD36^–CD19^– cells and CD19⁺ cells (both subsets sorted twice at day 14 from the cultures). PCR was performed on 20 000 cells, and Bcl-6 was used to monitor the integrity of DNA.