Process and apparatus for purifying and concentrating dna from crude

Abstract

A process and apparatus for purifying and concentrating DNA, which has relatively high molecular weight, from test samples containing DNA, for example from human whole blood samples; the collected DNA is of usable volume and concentration, and is of such purity as to permit conventional restriction by a number of enzymes without the need for further purification. The apparatus consists essentially of an agarose gel disc, typically 5 mm. thick by 31 mm. in diameter, immersed in an electrophoresis buffer solution and supported between two 8 micrometer polycarbonate filters in an electric field. Further, the method involves the loading of a suitably treated sample such as blood lysate onto the top face of the agarose gel disc and then applying an electric field. Of the constituent parts of the treated blood, the DNA molecules are the largest with regard to molecular weight. Consequently, their passage through the agarose gel disc, under the force of the electric field, is impeded. All other constituent parts of the treated blood pass relatively rapidly through the disc and are removed, being swept away by flow of the buffer solution. The DNA is then eluted and collected, in concentrated form by application of the electric field, while the normal flow of buffer solution between the bottom of the gel matrix and a collection chamber is prevented.