Mix & Go! XJa (DE3) Autolysis Competent Cells


Mix & Go! XJa (DE3) Autolysis Competent Cells


Cat # Name Size Price Quantity
T3031 Mix & Go! XJa (DE3) Autolysis Competent Cells, 1 ml 500x L-Arabinose 10 x 100 µl $219.00
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Mix & Go! XJa (DE3) Autolysis Competent Cells


  • Fast: 80 - 90% of E.coli are lysed in only 10 minutes after harvesting.
  • Simple 20 Second Transformation: No heat shock! Just add DNA and spread.
  • DE3 Lysogen: Encodes the T7 polymerase for expressing recombinant proteins under the control of the T7 promoter.


While there are many cell lysis methods available to scientists, unfortunately none of these methods combine all the ideal features for simple, efficient, economical, and gentle lysis of E. coli cells. The E. coli XJ autolysing strains from Zymo Research were engineered to address this problem. Mild expression of a chromosomally encoded bacteriophage λ R gene, encoding the λ lysozyme, also known as λ endolysin, is induced during growth. Cells are harvested intact while the peptidoglycan layer of the cell walls has been protected from digestion by the cytoplasmic membrane. The membrane is, however, amenable to disruption by a brief physico-chemical stress such as a freeze-thaw cycle after harvesting the cells. The XJ Autolysis™ method is highly efficient and takes only minutes (unlike traditional multiple freeze-thaw cycles). It can be applied to any number of samples without increasing processing time and labor (unlike sonication or French-press), is reliable and repeatable (unlike lysozyme treatment), and finally, is fully compatible with a wide range of buffers. Additionally, it does not require use of any potentially interfering components such as detergents, commonly found in various lytic buffers. They are also applicable for nucleic acid purification, and available with a DE3 lysogen encoding the T7 polymerase for expressing recombinant proteins driven by the T7 promoter.

Technical Specifications

Autolysis Lyses easily. 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. 80-90% of E. coli are lysed after a single freeze-thaw treatment.
Cell Growth Grows well, especially when medium is supplemented with 1 mM Mg2+
DNA Extraction This strain is EndA- and yields high quality DNA preparations.
DNA Stability The RecA- mutation in XJa stabilizes repetitive DNA sequences.
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), λ(DE3)
Processing Time 10 minutes
Product Storage -70°C to -80°C
Protein Expression Suitable for general screening, but proteases may degrade small or otherwise unstable recombinant proteins.
Transformation Efficiency 108 - 109 transformants per µg of plasmid DNA

Product FAQ

Q1: Can glycerol be present during the freeze-thaw cycle?

Q2: What if the lysate is extremely viscous?

Q3: How do you improve lysis efficiency?

Q4: Will chitin be degraded?

Q5: Is a starter culture necessary?

Q6: Can glucose be added to the growth media?

Q7: What buffer should the cell pellet be resuspended in?

Q8: Are competent cells GMOs?

Q9: Are the Mix & Go! strains dam+ and dcm+?

Q10: Do the Mix & Go! strains methylate DNA?

Q11: Which strains are equivalent to the Zymo strains?

Q12: How to reduce satellite colonies on agar plates?

Q13: Is it possible to dilute the competent cells?

Q14: Which antibiotics can be used with the Mix & Go! procedure?

Q15: Which Plasmid Size can be used for transformation?

Q16: Which is the recommended DNA concentration and volume for transformation?

Q17: What are some tips to improve transformation efficiency?

Q18: How will a heat-shock affect my Transformation Efficiency?


To clone new GFP-like fluorescent proteins from Obelia medusa, the authors identified the potential genes using expression libraries and cloned the genes into a vector. Expression of the proteins was facilitated by using XJb Autolysis E. coli cells from Zymo Research. The authors were able to purify three proteins from Obelia medusa that fluoresce in three different colors: cyan, green, and yellow.

Aglyamova, G.V. et al. (2011) Multi-colored homologs of the green fluorescent protein from hydromedusa Obelia sp. Photochem Photobiol Sci (8):1303-9.