Mixed triblock copolymers used as DNA separation medium in capillary electrophoresis

A polymer solution, formed by mixing two polyoxybutylene-polyoxyethylene-po lyoxybutylene (BEB) triblock copolymers (B10E270B10 and B6E46B6), was teste d as a new separation medium for double-stranded DNA separation in capillar y electrophoresis. The mixture of B10E270B10 and B6E46B6 has a viscosity-ad justable property and a dynamic coating ability, which makes the medium ver y easy to handle. The performance of the mixture on the DNA separation is g reatly affected by the mass ratio of the two constituents. There is a minim um amount of concentration for B10E270B10, below which the medium will lose its performance. The addition of B6E46B6 increases both the selectivity an d the separation efficiency. The optimal concentration, with 3% (w/v) B10E2 70B10 and 5% (w/v) B6E46B6, is determined with the consideration of both sp eed and resolution. A resolution of 1.3 was achieved on the separation of 1 23/124 base pairs in the pBR322/HaeIII digest within 20 min by using a 10 c m column of 75 mum I.D., demonstrating the potential use of mixtures of amp hiphilic block copolymers as an effective DNA separation medium. (C) 2001 E lsevier Science B.V. All rights reserved.