MEFcellsserveasfeedercellsthatsupportthegrowthofundifferentiatedmouseorhumanembryonicstemcells(ESCs)andinducedpluripotentstemcells(iPSCs).MEFcellsareisolatedfrom13.5-dayoldmouseembryosandshouldbeusedatearlypassages.Beforeuseasfeedercells,MEFcellsmustbemitoticallyinactivatedbyγ-irrADIationormitomycin-Ctreatment.|DR4MEFcellsarederivedfrommicethataregeneticallyengineeredwith4drug-resistantgenes,neomycin,hygromycin,puromycinand6-thioguanine.||Treatment:|gamma-irradiated||CellType:|MouseEmbryonicfibroblasts||StorageandStABIlity:|Forlong-termstorage,aliquottoavoidrepeatedfreezingandthawingandStoreinliquidnitrogen.Formaximumrecoveryofproduct,centrifugetheoriginalvialafterthawingandpriortoremovingthecap.Aliquotsarestablefor6months.||Protocol:|1.Removeavialoffrozencellsfromliquidnitrogenandplaceitontodryicefor5’beforethawingitat37ºCwaterbath.Assoonasthemajorityofthecontentofthevialthawed,transferittoaconicaltubecontaining10xvolumeofpre-warmedmedium.||2.Spinat1000rpmfor5min,discardmedium,resUSPendthecellsingrowthmediumandplatethematanappropriatedensityinagelatin-coatedtissue-culturedish(generally25,000-50,000cells/cm2,AppendixIII).Optimaldensityistobedeterminedbytheuserforspecificapplications. USBio的生物化学品，抗体，重组蛋白，细胞培养基和分子生物学试剂盒几乎用于所有科学应用和环境，包括基因组研究，生物技术，药物开发和疾病诊断。USBio产品从经济实惠的研究数量到更大的批量可用于工艺开发和生产。我们的客户包括位于美国和国外的大多数*的制药和生物技术公司。