R5421(CY162) Chemically Competent Cell

For the first use of Carrier DNA，boil the tube containing Carrier DNA in boiling water for 5 min，then place it on ice immediately and store it at -20℃ after use for standby. Thaw Carrier DNA on ice before subsequent use，and re-denature Carrier DNA after 3-5 repeated freeze-thaw cycles. Competent cells are best thawed on ice. The use of high-concentration plasmids for transformation can correspondingly reduce the amount of bacterial solution used for final plating. Saccharomyces cerevisiae is temperature-sensitive with an optimal growth temperature of 28℃-30℃，and temperatures above 31℃ will affect yeast growth. Yeast grows slower in dropout medium than in YPDA medium，and the more deficient components in the medium，the slower the yeast grows. R5421 (also known as CY162) is a MATα haploid strain of Saccharomyces cerevisiae，which is mainly used for the heterologous functional complementation identification of potassium ion (K?) transporters，channels and pumps. Its transformation markers are ura3 and leu2. The strain can grow normally in medium containing 100 mM KCl and grows slowly in medium with 5–10 mM KCl; when the KCl concentration is lower than 0. 5 mM，the growth of R5421 (CY162) cells is arrested. The transformation efficiency of R5421 competent cells determined with pGADT7 plasmid (7988 bp，Amp?) is higher than 103 cfu/μg DNA. Genotype: MATα ura3-52 leu2 trk1Δ his3Δ200 his4-15 trk2Δ1::pCK64