TOP10F´ E. coli are identical to TOP10 cells, with the addition of an F´ episome. The F´ episome carries the tetracycline resistance gene and allows isolation of single-stranded DNA from vectors that have an f1 origin of replication. In addition, the F´ episome carries the lacIq repressor for inducible expression from trc, tac, and lac promoters using IPTG. TOP10F´ cells require IPTG induction for blue/white color screening.
TOP10F´ cells are lacIq and require IPTG to induce expression from the lac promoter. If blue/white screening is required to select for transformants, spread 40 µl of 40 mg/ml X-Gal in dimethylformamide and 40 µl of 100 mM IPTG on top of the agar. Let the X-Gal and IPTG diffuse into the agar for approximately 1 hour.
Introduction
Strains Resistance tetracycline resistance
Culture Medium LB
Condition 37℃ ,under the aerobic conditions
Genotype
F'[lacIqTn10(tetR)] mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 ΔlacX74 recA1 araD139 Δ(ara-leu)7697 galU galK rpsL endA1nupG
