Five-minute purification of PCR products by new-freeze-squeeze method

Author: Jin-Long Yang ^{1, 2}, Rui Yang ¹, An-Chun Cheng ^{2, 3*}, Ren-Yong Jia ², Ming-Shu Wang ² and Su-Hui Zhang ¹

Received 18 January 2010, accepted 22 April 2010.

Abstract

Here, we describe a new-freeze method (NFM) for rapid purification of PCR products. After PCR products were separated by horizontal common agarose electrophoresis, gel fragments containing the desired PCR products were directly subjected to NFM. The resulting gel was frozen in nitrogen canister for 60 s and thawed in 70°C for 2 min and then centrifuged. DNA in the supernatant was stored at -20°C until further use. PCR products in the size range of 100-2000 bp were purified within nearly 5 min. NFM could separate 2 DNA fragments that differed in length by 50 bp. As judged by the purification efficiency, the quality of PCR products separated by NFM was equal to that of the method of DNA purification by low-melting-agarose gel method (LMM) and freeze-squeeze method (FSM). NFM reduces the operational time and cost of recombinant DNA technology, in which purification of PCR products is a repetitive process. With no complicated equipment and technical training, NFM is very simple and easy to operate.

Key words: Agarose gel electrophoresis, new-freeze method, PCR, purification.