We have built an automated pulsed field capillary electrophoresis system on the basis of a commercially available device. Using entangled polymer solutions as separating matrix, we demonstrate a considerable improvement of separation of double-stranded DNA in the range of 1-50 kbp under pulsed field conditions. The influence of the main parameters, i.e. pulse frequency and electric field, is studied and the results are compared to existing electrophoresis theories.