Tert^tm2.1Sear

A compound epitope tag comprising a Staph protein A sequence, a Flag epitope and a triple HA epitope was inserted in frame upstream of the initiating methionine codon in exon 1. A floxed neomycin cassette was inserted downstream of exon 1. Targeting occurred in ES cells with a knock-in of tamoxifin-inducible cre recombinase. Tamoxifen incubation led to the removal of the neomycin selection cassette in correctly targeted ES cells. Telomerase activity was equivalent between homozygotes and controls as determined by telomerase activity from small intestine extracts. (J:150343)