Heteroduplex analysis of IGH gene rearrangements in precursor-B-ALL. (A) Homoduplex bands (size 310 bp) and heteroduplex bands of IGHV1-IGHJ are distinguished in lanes 1 to 4. M- Molecular weight marker. (B) Homoduplex bands (size 350 bp) and a smear of heteroduplex bands of IGHV2-IGHJ. (C) Homoduplex (size 300 bp) and heteroduplex bands of IGHV3-IGHJ. (D) Homoduplex (size 304 bp) and heteroduplex bands of IGHV4-IGHJ. (E) Homoduplex bands (size 340 bp) and a smear of heteroduplex for IGHV5-IGHJ; lane 3-a homoduplex band (size 356 bp) and a smear of heteroduplex for IGHV6-IGHJ rearrangement are shown.