Flp-In Flips Out
Flp-In Flips Out
Anyone who's ever made stable cell lines knows that clones can vary wildly in terms of expression levels. Some express the transfected gene at high levels, some express at low levels, and some, for whatever reason, fail to express at all. Individual clones must, therefore, be carefully screened. And, because integration sites are random, direct comparison of multiple clones can be uncertain. In 1999 Invitrogen of Carlsbad, Calif., unveiled its Flp-In™ recombinase-based system as a solut