[Preparation of chromosomal DNA from whole blood without use of phenol]

We describe in this paper a simple and efficient procedure for preparing peripheral blood DNA without pre-isolation of white blood cells. The method also avoids the hazard of organic solvent extraction. Routinely it yields 20 to 28 micrograms of chromosomal DNA from per ml whole blood. The A260/A280 ratio for DNA sample is 1.80 to 1.85. The undigested DNAs migrate above the 21 kb pair, while the endonucleasedigested samples appear characteristically in the smear form. These data illustrate the consistency and quality of the chromosomal DNA isolated using this procedure. The DNA prepared by this method was used for analysis of beta-thalassemia mutation and prenatal diagnosis in our laboratory.