Improved genomic blot hybridization

For restriction fragment length polymorphism (RFLP) and other molecular biology experiments, well prepared (undamaged) genomic DNA is needed, which is then digested with restriction enzymes, transferred to nitrocellulose paper and hybridized with radioactive or nonradioactive probe. DNA damage occurs in fields such as clinical genetics and forensic medicine in the form, for example, of single stranded breaks. If these DNAs are treated with T4 DNA ligase prior to restriction endonuclease digestion, the damaged DNA is repaired. This "repaired DNA" gives improved Southern hybridization results with single copy gene or repeated genes.