Genotyping of the cultured fetal liver cell lines.

Genomic DNA was extracted from the indicated tissue and subjected to Southern blot hybridization, as detailed in “Materials and methods.” (A) To determine the C/EBPα genotype,HincII-digested DNA was hybridized with the C/EBPα genomic probe. (B) To assess the relative number of retroviral vector integration sites, EcoR1-digested DNA was hybridized to theneo-specific probe.