Jaenisch protocol for Flp transfection in ES cells

1-2 million ES cells on plate

transfect with cytofectene 10ug CMV-Flp, 1ug CAGGS-Flp-IRES-Puro

24 hours post-transfection add puromycin at 2ug/mL, which will kill most untransfected cells

Feed with puromycin again at 48 hours post-transfection

Switch back to non-selective media at 60 hours post-transfection

Pick clones when visible and screen

Expect loopout to approach 100%, and must screen to R/O Flp/puro integration