Stellar Electrocompetent Cells for cloning

Our Stellar Electrocompetent Cells provide high transformation efficiency, making them suitable for many molecular biology applications, such as generation of cDNA libraries or constructing gene banks. This E. coli strain can be used in place of DH10B cells and has several useful features. The recA1 and endA1 markers in the strain minimize recombination and degradation of plasmid DNA. These electrocompetent cells, based on the HST08 E. coli strain, provide alpha-complementation of the beta-galactosidase gene for blue/white screening of recombinant colonies (positive clones).

Stellar Electrocompetent Cells lack the gene cluster which digests foreign methylated DNA (mrr-hsdRMS-mcrBC and mcrA) and are therefore useful for cloning of methylated DNA, in addition to the construction of standard and longer-length genomic libraries.

Cat. #	Product	Size	Price	License	Quantity	Details
636765	Stellar™ Electrocompetent Cells	10 Transformations	USD $313.00
Stellar Electrocompetent Cells are an E. coli HST08 strain that provides high transformation efficiency, good reproducibility, and blue/white screening when paired with pUC plasmid vectors. These cells are specially made for transformation using the electroporation method. Stellar Electrocompetent Cells lack the gene cluster which digests foreign methylated DNA (mrr-hsdRMS-mcrBC and mcrA), and are therefore useful for cloning of methylated DNA, in addition to construction of genomic libraries and longer-length genomic libraries. A pUC19 vector is provided as well as SOC Medium. Notice to purchaser Our products are to be used for Research Use Only. They may not be used for any other purpose, including, but not limited to, use in humans, therapeutic or diagnostic use, or commercial use of any kind. Our products may not be transferred to third parties, resold, modified for resale, or used to manufacture commercial products or to provide a service to third parties without our prior written approval. Documents Components You May Also Like Image Data Back 636765: Stellar Electrocompetent Cells Back Stellar Competent Cells provided transformation efficiencies equivalent to or better than those obtained using DH5α or DH10B competent cells The high efficiency of Stellar Competent Cells was especially noticeable in the transformation of 10 kb and 20 kb plasmids. Using DNA plasmids of 2 kb (100 pg), 10 kb (1 ng), and 20 kb (1 ng), each strain of competent cells was transformed and plated on ampicillin-containing LB agar plates. Transformation efficiencies were determined based on the colony counts obtained. Back Stellar Competent Cells provided the highest transformation efficiencies for all the ligation reaction mixtures tested. The difference in transformation efficiencies of the competent cells was particularly prominent when cloning 20 kb fragments. Ligation reactions were set up with either 100 ng of a 2 kb, Hind III-cut DNA fragment + 50 ng of Hind III/BAP-cut pUC118 vector, or 75 ng of a 20 kb, Hind III-cut DNA fragment + 25 ng of Hind III/BAP-cut pUC118 vector. All reactions were performed at 16℃ for 6 hours using the Takara DNA Ligation Kit (Cat# 6023 or 6024). Each strain of competent cells was transformed using portions of these reaction mixtures and plated on ampicillin-containing LB agar (+ X-gal). Transformation efficiencies were determined based on the white colony counts obtained. Back Stellar Competent Cell colonies showed a faster growth rate than DH10B colonies Stellar colonies transformed with larger plasmid clearly showed a faster growth rate. DNA plasmids of 2 kb (Panel A) and 10 kb (Panel B) were each used to transform Stellar and DH10B competent cells with similar genetic characteristics, including methylation requiring restriction. This experiment used the same method as in Figure 1. Photographs of colonies on agar were taken after 15 hours of incubation.

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Transformation efficiency

>1 × 10⁹ cfu/µg

Genotype

F-, endA1, supE44, thi-1, recA1, relA1, gyrA96, phoA, Φ80d lacZΔ M15, Δ (lacZYA - argF) U169, Δ (mrr - hsdRMS - mcrBC), ΔmcrA, λ-

Applications

Cloning of large fragments
cDNA library construction
Genomic library construction
Long-length genomic library construction

Additional product information

Please see the product's Certificate of Analysis for information about storage conditions, product components, and technical specifications. Please see the Kit Components List to determine kit components. Certificates of Analysis and Kit Components Lists are located under the Documents tab.

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Stellar Electrocompetent Cells for cloning

Notice to purchaser

636765: Stellar Electrocompetent Cells

Stellar Competent Cells provided transformation efficiencies equivalent to or better than those obtained using DH5α or DH10B competent cells

Stellar Competent Cells provided the highest transformation efficiencies for all the ligation reaction mixtures tested.

Stellar Competent Cell colonies showed a faster growth rate than DH10B colonies

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Transformation efficiency

Genotype

Applications

Additional product information