BL21 Gen-X™ Competent E. coli

• Up to 10X greater expression of your recombinant proteins
• Reduced background protein levels, as much as several fold
• Detect proteins not visible if expressed in other BL21 strains
• Simple and straightforward protocol
• Compatible with all T7 promoter-based expression vectors

  The BL21 Gen-X™ E. coli is a new generation of BL21(DE3) that provides significantly higher levels of recombinant protein expression and significantly reduced levels of background protein levels compared to previous versions of BL21(DE3). **

  Cat. #	Contents	Quantity
  C600500	BL21 Gen-X Chemically Competent E. coli	10 X 50 ul
  	SOC Medium	3 ml
  	pUC19 Positive Control Plasmid	20 ul (10pg/ul)
  	Gen-X Induction Enhancer	10X 2 x 10 ml
  C601500	Gen-X Induction Enhancer 10X	500 ml

   

  Shipping & Storage

  BL21 Gen-X E. coli Chemically Competent E. coli are shipped frozen.
  For maximum stability and long-term use, store the cells and pUC19 control plasmid at -70ºC upon receipt.
  The Gen-X Induction Enhancer and SOC Medium should be stored at 4ºC or at room temperature.
  All components are guaranteed stable for 6 months when stored properly.
  *When using BL21 Gen-X kit and protocol, Genlantis guarantees more of your recombinant protein than standard BL21 (DE3) or your money back.
  ** Patent Pending

Figure 1. Comparison of protein expression from pET vectors in BL21 Gen-X and standard BL21 (DE3) E. coli cells.Ten 2 ml cultures of BL21 (DE3) each containing a different protein expression construct were grown at 37ºC in LB and induced with 1 mM IPTG at OD600 = 0.4. Cells were incubated overnight and 1 ml harvested. Concurrently, 2 ml cultures of BL21 Gen-X containing the same ten protein expression constructs were grown at 37ºC in M9 minimal media and induced with 1 mM IPTG at the same OD. Cells were incubated overnight and 1 ml harvested. For both strains, pellets were suspended in 100 μl, lysed, and 10 μl electrophoresed on 4-12% polyacrylamide gels. In lanes 1,3,4,5,6,8,9, and 10, the quantity of recombinant protein obtained from BL21 Gen-X cells was considerably greater and the background of endogenous E. coli proteins significantly lower > (Click for PDF)

The BL21 Gen-X cells were created through careful cycles of mutagenesis, enrichment, and testing, resulting in a novel and more powerful protein expression strain. By reducing the growth rate and optimizing other characteristics, Genlantis scientists have produced BL21(DE3) cells that are qualitatively distinct from previous generations of BL21(DE3) E. coli.

Figure 2. Comparison of protein expression from pET vectors in BL21 Gen-X E. coli with and without addition of the Gen-X Induction Enhancer. Cells were grown and induced as described in Figure 1. Additionally, l of the 10X Gen-X Induction Enhancer were added at the time of IPTG addition; downstream processing was the same. For many constructs, the addition of the Gen-X Induction Enhancer noticeably reduced background protein expression. In some instances, there is a decrease in absolute recombinant protein expression. However, the net result is a protein yield of higher purity due to the relatively lower background. In other cases, the Gen-X Induction Enhancer is essential for abundant target protein expression; for example in Lane 2, the 60KDa recombinant protein was observed only in the BL21 Gen-X cells along with the Gen-X Induction Enhancer, while in lane 8, the induction enhancer was responsible for increased expression of the 69 KDa protein (Click for PDF)

The results are striking: BL21 Gen-X, along with the powerful Gen-X Induction Enhancer, will express more of what you want, and less of what you don't want. For example, the BL21 Gen-X cells are able to express proteins that are not expressed or detected at all using other popular BL21 cells or kits. (see Figure 2, lanes 2)