in-competent cells - (May/09/2004 )

Hi, I'm trying to transform ultra-competent cells (XL10) but to no avail.... there are only ever a couple of colonies on the plate and even the puc18 control will not work. I've followed the protocol, so what could be up?

Sounds like you figured it out.. incompetent. Were they always stored at -80? I would try getting an aliquot from somewhere else and do a parallel reaction with your cells to confirm this.