Modification of protcol for isolation and purification of genomic DNA

A simple and efficient modified protocol for the extraction of high quality of genomic DNA from roots of Salacia oblonga collected from the three different places (Agumbi, Jogimat, Badsii) in Kerala, has been developed. The important modification steps in this CTAB (hexa decacyl trimethyl ammonium bromide) protocol include (a) use of 3.5 M NaCl in extraction buffer, (b) 2M NaCl during precipitation (c) Tris – saturated phenol in place of phenol: choloroform: isoamyl alcohol at purification phase (d) 80% ice cold ethanol for DNA precipitation and at last (e) performing all the reactions at room temperature. The DNA thus extracted from roots have 1.36, 1.7, 1.26 OD at A 260/280 and the yield was 68, 87, 143 μg/g material. The extracted DNA was found to be suitable for DNA fingerprinting technique, RAPD (Random amplified polymorphic DNA) for development of molecular markers studies on genetic diversity. Three different samples (Agumbi, Jogimat, Badsii) in Kerala were subjected to RAPD analysis using 15 different random decamer primer. Out of 15 primers, the amplification was obtained only in 3 primers producing 29 bands showing the greatest genetic polymorphism between the samples.