There exists a wide variety of ready to use DNA isolation kits and reagents to isolate DNA from different sources. However, since the purity of DNA known from the ratio of absorbance of DNA at 260nm to 280 nm affects the downstream works with DNA in molecular biology, the question of high quality of DNA free from protein contamination plays an important role. We propose here an improved method of DNA isolation that gives a ratio of A260/A280 more than 2.0 suitable for PCR and sequencing applications.Isolation of DNA from animal tissues is early step to characterize the change in nucleotide sequences due to mutations. This characterization of sequence change is verified either by PCR (polymerase chain reaction) or DNA sequencing. The purity of DNA constitutes an essential step before applying molecular techniques. Although there exist a variety of protocols (1,2,3) but the current protocol is a modification of existing phenol chloroform method to gives surety of a ratio of A260/A280 more than 1.9 compared to earlier protocols.
Key words: DNA, Isolation, Tissue, OD, Purity
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