MultiShot™ FlexPlate Stbl3™ Competent Cells (Invitrogen™)

MultiShot FlexPlate Stbl3 Chemically Competent E. coli cells are cloning competent cells that are pre-aliquoted in a 96-well PCR plate to increase transformation productivity. The FlexPlate format can be divided down to any combination of 8-well segments to allow for flexibility in transformation throughput.

Achieve remarkable stability of lentiviral vectors in Stbl3
MultiShot FlexPlate Stbl3 Competent Cells are designed for cloning direct repeats found in lentiviral expression vectors as these cells reduce the frequency of homologous recombination of direct repeats found in lentiviral vectors (e.g., ViraPower Lentiviral Expression kits) and other retroviral vectors (e.g., instability-prone HIV-based plasmids). The Stbl3 strain has been used for many applications, including genome editing CRISPR workflows (the first original protocol by Zhang group in 2013), vaccine development (including SARS-CoV-2 vaccine research), and cloning and maintaining vectors with multiple repeats (e.g., gene coding protein with repeated sequence). The transformation efficiency of MultiShot FlexPlate Stbl3 chemically competent E. coli cells is >1 x 10⁷ cfu/μg plasmid DNA.

The Stbl3 E. coli strain is derived from the HB101 strain (with a hybrid K-12 and B strain genome). Though the Stbl3 strain contains the recA13 allele of the recA mutation that reduces nonspecific recombination occurrence in cloned DNA, the ability of the Stbl3 strain to maintain unstable inserts is reportedly driven by other genetic traits. Mutations in the Stbl3 methylation-dependent restriction system (mcrB, mrr, and hsdS20) allow construction of cloning genomic DNA. This strain is endA1+, thus a nonspecific endonuclease I that digests DNA is present in the cells. Stbl3 reproducibly yields much more plasmid DNA than DH strains (e.g., 10-fold or more plasmid DNA than the TOP10 strain) and sustainably produces high titer lentivirus.

MultiShot FlexPlate Stbl3 Competent Cells offer:
• Expected efficiency of >1 x 10⁷ transformants/μg plasmid DNA
• Optimal performance for the propagation of lentiviral vectors and maintenance of direct repeats
• Enhanced genomic DNA cloning capacity (mcrB, mrr, and hsdS20)
• Cability to produce high DNA yields

Note: For optimal performance, Stbl3 cells should be cultured at 30°C to maintain plasmid with complex repeat sequences. When performing plasmid DNA isolation from Stbl3 cells that have wild type endonuclease I (endA1+), ensure that buffers contain 10 mM EDTA. EDTA will inactivate the endonuclease and avoid DNA nicking and vector degradation (follow plasmid DNA purification kit instructions for endA1+ E. coli strains).

Increase transformation productivity with MultiShot FlexPlate format
The FlexPlate is a 96-well PCR plate that can be used in automated liquid handling systems or divided into 8-well segments for flexibility in transformation throughput. Addition of DNA to the MultiShot FlexPlate Competent Cells can be quickly performed with a multichannel pipet or a liquid handling system. After addition of DNA, the cells can be efficiently transformed by heat-shock using a water bath, heat block, or thermal cycler.

Key benefits of the MultiShot FlexPlate format include:
• Increase throughput—compatible with automated liquid handling platforms
• Flexible—transform in increments of 8 wells to entire 96-well plate 
• Convenient—competent cells pre-aliquoted into 96-well plate, ready for transformation

Genotype
F^–mcrB mrr hsdS20(rB–, mB–) recA13 supE44 ara-14 galK2 lacY1 proA2 rpsL20(StrR) xyl-5 λ–leu mtl-1

Find the strain and format that you need
Other Stbl strains are available with different genetic background. A variety of E. coli strains and formats of chemically competent cells and electrocompetent cells are also available to help meet your specific transformation needs. For high-throughput transformation, choose from our collection of MultiShot formatted comp cells or email us for custom formatting options. We offer bacterial growth media in various formats.