TY - JOUR A1 - Peitz, Michael A1 - Jäger, Richard A1 - Patsch, Christoph A1 - Jäger, Andrea A1 - Egert, Angela A1 - Schorle, Hubert A1 - Edenhofer, Frank T1 - Enhanced purification of cell-permeant Cre and germline transmission after transduction into mouse embryonic stem cells T2 - Genesis N2 - Continuous expression of Cre recombinase has the potential to yield toxic side effects in various cell types, thereby limiting applications of the Cre/loxP system for conditional mutagenesis. In this study, we investigate the potential of Cre protein transduction to overcome this limitation. COS-7, CV1-5B, and mouse embryonic stem (ES) cells treated with cell-permeant Cre (HTNCre) maintain a normal growth behavior employing Cre concentrations sufficient to induce recombination in more than 90% of the cells, whereas continuous application of high doses resulted in markedly reduced proliferation. HTNCre-treated ES cells maintain a normal karyotype and are still able to contribute to the germline. Moreover, we present an enhanced HTNCre purification protocol that allows the preparation of a concentrated glycerol stock solution, thereby enabling a considerable simplification of the Cre protein transduction procedure. The protocol described here allows rapid and highly efficient conditional mutagenesis of cultured cells. Y1 - 2007 UR - https://pub.h-brs.de/frontdoor/index/index/docId/3751 SN - 1526-954X VL - 45 IS - 8 SP - 508 EP - 517 PB - Wiley-Blackwell ER -