“…A 1.3-kb BamHI-EcoRI fragment contains the JH3 and J segments. VH family-specific probes were isolated as a 1.3-kb BamHI-EcoRI fragment from VH 3609P (Riblet et al, 1986), a 270-bp PstI fragment from the cDNA 93G7 (Sims et al, 1982) that hybridizes to the J558 VH gene family, a 600-bp EcoRI-XbaI fragment from M460 that is specific for the 3660 VH family (Dzierzak et al, 1985), a 500-bp XholI fragment from VGAM3-8 that hybridizes to the VGAM3-8 VH family (Winter, et al, 1985), a 450-bp PstI fragment from S107 (Crews et al, 1981), a 600-bp fragment from pBV14 that detects the J606 family, a 500-bp EcoRI-PstI fragment from VH 39 that hybridizes to the X24 family (Hartman and Rudikoff, 1984), a 320-bp EcoRI-HindEll fragment from VHQ52 , and a 280-bp PstI-EcoRI fragment from VH 81X that recognizes the 7183 VH gene family (Yancopoulos et al, 1984). Southern filter hybridization Fifteen micrograms of liver or B cell DNA was digested with the indicated restriction endonuclease (Boehringer Mannheim), applied to an 0.8% agarose gel and electrophoresed in the presence of 0.094 M Tris, pH 8.0, 0.02 M sodium citrate, 0.0175 M NaCI and 0.2 mM ethylenediaminetetraacetic acid at 85 mAmps for 16-18 h. The size-fractionated DNA was then transferred to nitrocellulose (Schleicher and Schuell) and pre-hybridized in the presence of 50% formamide (BRL) as described (Sims et al, 1982).…”