A SIMPLE AND FAST PROCEDURE FOR HIGH-QUALITY DNA ISOLATION FROM GELS USING LAUNDRY DETERGENT AND INVERTED COLUMNS

A quick method for the recovery of DNA from agarose and polyacrylamide gels with high efficiency and quality is described. Excised gel slice s, containing at least 10 ng DNA, are incubated for 15 min at 60 degre es C in the presence of laundry detergents. An ''inverted column'' is obtained by covering the extraction liquid by a layer of cotton wool, Sephadex G-50 and another layer of cotton wool. Following centrifugati on the supernatant containing the DNA is recovered by aspiration and t he DNA is precipitated with isopropanol and tRNA, washed with ethanol and air-dried. The yield of reisolated DNA does not depend on DNA frag ment size and small quantities of gel volume. Thus, the technique may prove useful in a broad range of applications in the methodology of mo lecular biology.