A simple salting out procedure for extracting DNA from human nucleated cells

One of the obstacles encountered when extracting DNA from a large number of samples is the cumbersome method of deprotein-izing cell digests with the hazardous organic solvents phenol and isochloroform. Several other non-toxic extraction pro-cedures have been published, but require either extensive dialysis (1) or the use of filters (2). A rapid, safe and inexpensive method was developed to simplify the deprotein-ization procedure. This method involves salting out of the cellular proteins by dehydration and precipitation with a saturated NaCl solution. Buffy coats of nucleated cells obtained from anticoagulated blood (ACD or EDTA) were resuspended in 15 ml polypropylene centrifugation tubes with 3 ml of nuclei lysis buffer (10 mM Tris-HClt 400 mM NaCl and 2 mM Na2EDTA, pH 8.2). The cell lysates were digested overnight at 37°C with 0.2 ml of 10Z SD