Affinity isolation of transcriptionally active DNA

Chicken erythrocyte nuclei were nick translated with the chemically cleavable biotinylated nucleotide. Bio-12-SS-dUTP. DNA was purified, digested with restriction endonucleases, and applied to an avidin-agarose affinity column. Seventy percent of the nick translated DNA bound to the column. This DNA was recovered from the column by chemical cleavage of the linker arm joining biotin to the DNA. Dot hybridization analysis of this DNA revealed a significant enrichment of the alpha-D-globin gene. This result suggests an approach to isolate transcriptionally active genes.