Sequence of der(11) in individual subclones, 34-1, 34-6, and 34-15, from panhandle PCR. The 5′ 3,651 bp include MLL forward nested primer and MLL bcr sequence. The 3,224 bp of 3′ sequence are partner DNA. The most 3′ 75 bp of sequence extend from ligated phosphorylated oligonucleotide (P-Oligo) through reverse nested primer. Sequencing strategy and orientation of sequencing primers are shown at bottom. Primers ALL-1-SQ7 and ALL-1-SQ8 identified the breakpoint in subclone 34-1 and verified the breakpoint in subclones 34-6 and 34-15. Comparison with normal MLL genomic sequence localized the breakpoint to nucleotide 3802. The insert at middle is the breakpoint junction sequence in subclones 34-1, 34-6, and 34-15, where the arrow shows the breakpoint. The partner DNA includes two unique nonrepetitive sequences 867 bp and 912 bp in size, Alu and THE1b MaLR repeats, and a 3′ region of homology to 255 bp of existing sequences of known ESTs. Each subclone ended at the 3′ side with the ligated oligonucleotide and MLL reverse nested primer sequence. Sequences were the same in all three subclones. Further sequencing of EST H73415 in entirety in forward and reverse directions showed homology at 1,033 of 1,034 bases in the indicated region (shadowed). S/R indicates a 267-bp region amplified in somatic cell hybrid and radiation hybrid screens.