This is a broadly used screening technique that find several genomic mutations in wide number of samples, this technique finds sequence variations because of point mutations or other mutations by electrophoretic mobility difference, as dna that includes a sequence mutation has a calculable mobility difference as compared to wild type dna when exposed to non denaturing conditions.
This technique includes 4 steps
1. Digestion of genomic dna through restriction endonucleases
2. Denaturation in alkaline solution.
3. Electrophoresis on neutral polyacrylamide gel.
4. Transfer it to a nylon membrane.
5. Hybridisation by either dna fragments or rna copies synthesized on each strand like probes.
Denaturing high pressure liquid chromatography is latest technique and is very useful for screening of large number of sample of mutations, top for germ line mutations, this echnique includes heteroduplex formation among wild type and mutated dna strands to find mutations. Hetro duplex molecules are segregated from homoduplex molecule through ion pair, reverse liquid chromatography on a special matrix along with partial heat denaturation of the dna strands.