POT1a exon 3 is floxed by two loxP sequences. Pot1a gene can be deleted by transduction of Cre recombinase to the MEFs. This inducible POT1a knockout MEF line is useful in studies of telomere biology. For detailed description, please look at a schematic of Flox allele (Fig. 2A and Suppl.) in (Hockemeyer, 2006).
Immortalization process: Infection of pBabe neo SV40-LT. The MEFs were harvested at E13.5 and were infected with pBabe Neo SV40-LT for immortalization. Cells were maintained for 3 weeks and frozen down. One of the vials was defrosted, expanded to two 15 cm dishes, and 10 vials of frozen stock were made for this deposition.
One vial was defrosted and tested for recovery rate, mycoplasma contamination, and genotype.