High speed separation of DNA fragments by capillary electrophoresis in poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock polymer

The high speed separation of DNA fragments by using a triblock copolpmer, 25% w/v F127 (PEO99PPO69PEO99 with PEO and PPO denoting polyethylene oxide and polypropylene oxide, respectively) which is easy to handle and does not need coating of the quartz capillary, has been investigated. Two ways to decrease the run time are presented: one is to shorten the effective capillary length and the other to increase the electric field strength. In a short capillary, the sieving ability of the separation medium versus the initial band width, and the band width spreading as a function of distance traveled dominate the resolution; at high electric field strength, Joule heating could deteriorate the separation. By taking both effects into account, the Phi X174/HaeIII digest could be separated within 100s by using an 8 mm effective length, 50 mu m diameter capillary operating at 300 V/cm.