V_hDJ_h as well as DJ_h rearrangements in the Hμ-locus in the EB34-pre-B and ES-pre-B cells. Large molecular weight DNAs from adherent (ad) BM-pre B cells, nonadherent (non-ad) BM-pre-B cells, ES-pre-B cells, adherent EB34-pre-B cells, nonadherent EB34-pre-B cells, LAK34a-1 cells, LAK34a-3 cells, and OP9 cells were subjected to PCR analysis using the D_SF sense primer and the J_h4 antisense primer for DJ_h recombinations (top), and the V₇₁₈₃ sense primer and the J_h4 primer for detecting V_hDJ_h recombinations (middle), and the α-actin primers (bottom), and separated on 1.2% agarose gels. Specificity of the DJ_h as well as V_hDJ_h products were further ensured by Southern blotting, followed by visualization with the J_h probe.16