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| • | Straightforward transformation procedure with up to 108 - 109 transformants/µg plasmid. |
| • | Simple, fast, and controlled autolysis of E. coli. |
| • | Available with DE3 lysogen for T7 promoter transcription. |
| Product | Catalog No. | Format | Price | Store |
|---|---|---|---|---|
| XJa Autolysis™ | T5021 | 1 glycerol stock 1 ml 500X L-Arabinose |
$ | |
| T3021 | 10 x 100 µl Z-competent cells 1 ml 500X L-Arabinose |
$ | ||
| XJa(DE3) Autolysis™ | T5031 | 1 glycerol stock 1 ml 500X L-Arabinose |
$ | |
| T3031 | 10 x 100 µl Z-competent cells 1 ml 500X L-Arabinose |
$ | ||
| XJb Autolysis™ | T5041 | 1 glycerol stock 1 ml 500X L-Arabinose |
$ | |
| T3041 | 10 x 100 µl Z-competent cells 1 ml 500X L-Arabinose |
$ | ||
| XJb(DE3) Autolysis™ | T5051 | 1 glycerol stock 1 ml 500X L-Arabinose |
$ | |
| T3051 | 10 x 100 µl Z-competent cells 1 ml 500X L-Arabinose |
$ | ||
| Components Available | ||||
| Protocol Time | 10 minutes |
| Lysis Method | Enzymatic, by intracellularly expressed λ-endolysin |
| Efficiency | 80-90% cells are lysed after a single freeze-thaw treatment |
| Convenience | Compatible with most buffer systems and with any other physical methods of lysis. |
XJ Autolysis™ E. coli strains are a new alternative for bacterial transformation and lysis. These strains are efficiently lysed following arabinose-induced expression of the bacteriophage λ endolysin protein, coupled to a single freeze-thaw cycle. The strains simplify protein expression and purification, and are also applicable for nucleic acid purification. They are also available with a DE3 lysogen encoding the T7 polymerase for expressing recombinant proteins driven by the T7 promoter.
| XJa Autolysis™ (E. coli, K-strain JM109) |
XJb Autolysis™ (E. coli, B-strain BL21) |
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|---|---|---|---|---|
| Cell Growth | Grows quite well, especially when media is supplemented with 1 mM magnesium. | A very robust strain, reaching higher OD’s than E. coli K-strains. | ||
| Autolysis | This strain lyses very easily. Actually, the parent strain JM109 itself will release about 20% of cellular protein after one freeze-thaw cycle. This strain will lyse in a wide range of buffer conditions. | XJb lysis efficiency is 10-20 % lower than XJa. For optimal lysis, more care needs to be taken when selecting the lysis buffer. However, even very low concentrations of a detergent improve lysis significantly. | ||
| Protein Expression | Suitable for general screening, but proteases may degrade small or otherwise unstable recombinant proteins. | XJb is ideal for recombinant protein expression. It lacks Lon and OmpT proteases, leading to higher protein yields. | ||
| DNA Extraction | This strain is EndA negative and yields high quality DNA preparations. | XJb is not optimal for DNA extraction | ||
| DNA Stability | The RecA negative mutation in XJa stabilizes repetitive DNA sequences. | This strain is RecA positive. | ||
| Genotype | F`[traD36 proA+B+ laclq ∆(lacZ)M15] ∆(lac-proAB) glnV44 (supE44) e14- (McrA-) thi gyrA96 (NalR) endA1 hsdR17(rK- mK+) relA1 recA1 ΔaraB::λR, cat (CmR) | F- ompT hsdSB(rB- mB-) gal dcm ΔaraB::λR, cat (CmR) |
