A New DNA Extraction Method for Plant Cells

Abstract

Current standard methods for the preparation of plant DNA exhibit some limitations: the use of water-saturated phenol for deproteinization can lead to the loss of DNA² satellites¹; the chloroform-octanol method does not extract membrane-bound DNA² and therefore heterochromatic DNA sequences can be lost. Thus, it became necessary to develop a quantitative and reproducible method for the systematic preparation of plant DNA, particularly as the difficult to extract DNA sequences seem to play a special role in cellular regulation³. The procedure used is the following: the lyophilized material is ground, treated with sodium dodecyl sarcosinate and deproteinized successively by a saline solution and by pronase after a pancreatic RNAse treatment. DNA is analyzed by sedimentation velocity for the determination of its molecular weight, by analytical thermal denaturation for the verification of its native state, while its purity is estimated by OV absorption at 230, 260 and 280 nm.