DNA isolation method for high polysaccharide Lesquerella species

A prerequisite for molecular genetic studies is the ability to isolate DNA. In species of the genus Lesquerella, high polysaccharide content makes thi s basic requirement difficult to achieve. The carbohydrates and the nucleic acids coprecipitate during sample preparation and form large pellets where the DNA is trapped in gum and is no longer retrievable. A DNA isolation me thod was developed to solve this problem. After breaking down the cell wall s, the cell nuclei are separated from the cytoplasmatic and intracellular f luids by centrifugation in a viscous medium. This preparatory step separate s the nuclei that contain the desired DNA from other cellular compartments containing the problem-causing carbohydrates. The DNA is then isolated from the nuclei without interference. High quality DNA was obtained and used su ccessfully for restriction endonuclease digestion and polymerase chain reac tion amplifications. (C) 1999 Elsevier Science B.V. All rights reserved.