Description

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 37°C 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 37°C 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, 220 μl 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.  This is because the Gen-X Induction Enhancer further reduces the growth rate of the cells.  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)

With the BL21 Gen-X Competent E. coli Expression Kit, there is now a

better way to express your recombinant proteins. The resulting higher

yields and lower background will make downstream purification and

processing of your recombinant proteins much easier, saving you

significant time and money

Contents

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

Shipping & Storage

The 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.
** Patent Pending