A technique that is used to compare DNA from two different species, to locate or identify nucleotide sequences, and to establish the effective in vitro transfer of nuclear material to a new host. A single strand of DNA from one source is bound to a special filter to which is added a single strand of radioactively labelled DNA from a different source. Complementary base pairing between homologous sections of the two DNAs results in double-stranded hybrid sections that remain bound to the filter, whereas single-strand sections are washed away. The amount of radioactivity remaining on the filter, compared with the amount washed away, gives a measure of the number of nucleotide sequences that the radioactive DNA and the original DNA share in common.
Subjects: Zoology and Animal Sciences.