Dear Wulf. we have relatively good results using the method of Inoue (described in Sambrook and Russell) for the production of chemically competent cells. As strain we use quite often E.coli DH5alpha (blue/white cloning possible).
It is really difficult to get a cfu of 109 but 108 up to 5*108 is possible with this method. In rare cases I got 109, but I tend to use the lower value to be on the safe site. The cells are used successfully for a lot of mutagenesis experiments and standard cloning. HTH Christian -- Christian Roth Institut für Bioanalytische Chemie Biotechnologisch-Biomedizinisches Zentrum Fakultät für Chemie und Mineralogie Universität Leipzig Deutscher Platz 5 04103 Leipzig Telefon: +49 (0)341 97 31316 Fax: +49 (0)341 97 31319