Competent Cells Selection Guide
All Epicentre Competent Cells have the following
features:
| Endonuclease A is a DNase that can survive boiling
lysis and can degrade plasmid DNA, reducing the DNA yield from plasmid
purifications. |
| A deletion in the lacZ gene which codes for
part of the amino-terminal of the β-galactosidase enzyme. A
plasmid containing sequences of the amino terminus can complement
this deletion to give functional β-galactosidase. When X-gal
is used as the substrate, β-galactosidase produces a blue product;
the colonies of these cells appear blue. When the complimentary sequence
on the vector is disrupted by inserting a cloned fragment of DNA,
the enzyme is no longer functional and cannot produce a blue product;
the colonies of these cells are white. On a plate of mixed blue and
white colonies, the white colonies should contain the cloned DNA. |
| The recA gene codes for a DNA-dependent ATPase
that is essential for genetic recombination in E. coli. Bacterial
strains deficient in recA are defective in recombination.
Plasmids in these strains are maintained as monomers (do not form
multimeric circles) and are less likely to incur deletions. |
| Restriction systems are designed to protect bacterial
cells from foreign DNA. Deleting the host cells' restriction system
allows efficient cloning of DNA with different methylation patterns,
such as DNA found in mammals, higher plants, and many prokaryotes. |
Electrocompetent E. coli
| TransforMax™ EC100™ | No | EC10005
5 x 100 µl EC10010
10 x 100 µl | >1 X 1010 | No | 145 kb | General Purpose |
| TransforMax™
EC100™-T1R | Yes | EC0205T1
5 x 100 µl | >1 X 1010 | No | 145 kb | General Purpose |
| TransforMax™
EC100D™ pir+ | No | ECP09500
5 x 100 µl | >5 X 109 | R6Kγori
15 copies/cell | Up to 100 kb | Rescue cloning using EZ-Tn5™ or HyperMu™ Transposome™ Complexes |
| TransforMax™
EC100D™ pir-116 | No | EC6P095H
5 x 100 µl | >5 X 109 | R6Kγori
250 copies/cell | Up to 50 kb | Rescue cloning using EZ-Tn5™ or HyperMu™ Transposome™ Complexes |
| TransforMax™ EPI300™ | No | EC300105
5 x 100 µl EC300110
10 x 100 µl EC300150
50 x 100 µl | >1 X 1010 | Vectors containing both F-factor and oriV
replicons | At least 145 kb Good for Libraries | Use with CopyControl™ Vectors for inducible single to
multiple copies/cell Clone toxic genes and unstable DNA |
| TransforMax™
EPI300™-T1R | Yes | EC02T15
5 x 100 µl EC02T110
10 x 100 µl | >1 X 1010 | Vectors containing both F-factor and oriV
replicons
| At least 145 kb Good for Libraries | Use with CopyControl™ Vectors for inducible single to
multiple copies/cell Clone toxic genes and unstable DNA |
| CopyCutter™ EPI400™ | Yes | C400EL10
10 x 50 µl | >1 X 1010 | ColE1-type
replicons | 145 kb | Controls copy number of common vectors Clone toxic genes and unstable DNA |
Chemically Competent E. coli
| TransforMax™ EC100™ | No | CC02810
10 x 50 µl | >1 X 108 | No | At least 23 kb | General Purpose |
| TransforMax™
EC100™-T1R | Yes | CCT10210
10 x 50 µl | >5 X 107 | No | At least 23 kb | General Purpose |
| TransforMax™ EPI300™ | No | C300C105
10 x 50 µl | >5 X 108 | Vectors containing both F-factor and oriV
replicons | At least 23 kb | Use with CopyControl™ Vectors for inducible single to
multiple copies/cell Clone toxic genes and unstable DNA |
| TransforMax™
EPI300™-T1R | Yes | CT1C0210
10 x 50 µl
| >5 X 108 | Vectors containing both F-factor and oriV
replicons | At least 23 kb | Use with CopyControl™ Vectors for inducible single to
multiple copies/cell Clone toxic genes and unstable DNA |
| CopyCutter™ EPI400™ | Yes | C400CH10 10 x 50 µl | >1 X 107 | ColE1-type replicons | At least 23 kb | Controls copy number of common vectors Clone toxic genes and unstable DNA |