A technique used for searching for a specific DNA fragment. The process is as follows:

  1. Separate DNA fragments with gel electrophoresis
  2. change pH of gel to basic, thus allowing disruption of hydrogen bonds
  3. blot gel with nitrocellulose paper
  4. heat paper so as to fix DNA fragments
  5. probe with labeled messenger RNA or cDNA
  6. wash
  7. complementary mRNA/cDNA fragments will have hybridized.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.