基因型：
F- ompT hsdSB (rB-, mB-) gal dcm rne131 (DE3)

基本信息：
抗性：无
培养基：LB
菌株类别：大肠杆菌
培养条件：37℃，有氧，LB
质粒转化：42℃热激
保存方式：20%甘油，-20℃
基本应用：用于蛋白表达
备注：

菌株简介：
BL21 Star (DE3) E. coli are chemically competent cells designed for applications that require high-level expression of non-toxic recombinant proteins from low copy number, T7 promoter-based expression systems (e.g., Champion pET vectors). BL21 Star (DE3) Chemically Competent cells are controlled for a transformation efficiency of 1 x 108 cfu/g plasmid DNA.
 A genotype that promotes high mRNA stability and protein yield
 Ideal for use with low copy number, T7 promoter-based plasmids
 The single tube, single use format allows all transformation steps to take Enhanced Expression of Non-Toxic Recombinant Proteins
BL21 Star (DE3) cells contain the DE3 lysogen that carries the gene for T7 RNA polymerase under control of the lacUV5 promotor, and IPTG is required to induce expression. This strain also offers enhanced mRNA stability due to a mutation in the RNaseE gene (rne131), which reduces levels of endogenous RNases and mRNA degradation, thereby increasing the stability of mRNA transcripts and increasing protein yield. Protein expression is further enhanced by the absence of the lon and outer membrane (OmpT) proteases, which reduces degradation of heterologous proteins.
The BL21 Star strains have higher basal expression of heterologous genes than BL21 strains, due to the increased stability of mRNA. Therefore, these strains may not be useful for expression of toxic genes.
BL21 Star(DE3)来源于BL21(DE3)菌株, 含有rne131基因突变体，rne131突变基因能够增强菌株细胞内mRNA的稳定性，从而有效提高蛋白表达能力。
主要适用于T7启动子载体的高水平蛋白表达。