Abstract
A simple elution tube has been constructed which allows reliable electroelution of DNA restriction fragments from agarose and acrylamide gels. This method enables the recovery of DNA fragments of 50 to over 50 000 base pairs from cylindrical or slab gels with yields between 70 % to 90 %. This method has several distinct features which make it outstanding. (1) It concentrates DNA from a large sample of gels into a small volume of buffer (less than 500 ฮผl) during elution oso that the recovered DNA can be directly precipitated out with alcohol for subsequent use. (2) The recovered DNA is contaminated with only a minimal amount of agarose or acrylamide gel so that it may be subsequently digested with most restriction endonucleases with normal efficiencies. (3) It is particularly useful for the recovery of DNA fragments that have been subjected to end labeling with [ฮณโ^32^P] ATP and polynucleotide kinase, because it not only recovers the DNA from the gel, but also purfies the fragments from the contaminating background [ฮณโ^32^P] ATP. (4) Many different sizes of DNA fragments can be recovered at the same time. In addition, the elution tubes are easy to construct with not much more cost than that of a piece of plexiglas tubing.