Description

Intact Genomics 5-alpha chemically competent E. coli cells are suitable for high efficiency transformation in a wide variety of applications such as cloning and sub-cloning. ig® 5-alpha chemically competent cells are at least twice the transformation efficiency of the nearest competitor.

Specifications

Competent cell type:  Chemically Competent
Derivative of:  5-alpha
Species:  E. coli
Format:  Tubes
Transformation efficiency:  ≥1 x 109 cfu/µg pUC19 DNA
Blue/white screening: Yes
Shipping condition: Dry ice

Reagents Needed for One Reaction

ig® 5-alpha Competent Cells:  50 µl
DNA (or pUC19 Control, 10 pg/µl):  1 µl
Recovery medium:  1 ml

Storage

ig® 5-alpha Competent Cells:  -80 ºC
pUC19 control DNA:  -20 ºC
Recovery medium:  4 ºC

Genotype

Φ80 Δ(lacZ)M15 fhuA2 Δ(argF-lacZ)U169 phoA glnV44 gyrA96 recA1 relA1 endA1 thi-1hsdR17

Quality Control

Transformation efficiency is tested by using the pUC19 control DNA supplied with the kit and using the high efficiency transformation protocol. Transformation efficiency should be greater than 1×109 CFU/µg pUC19 DNA. Untransformed cells are tested for appropriate antibiotic sensitivity.

General Guidelines

Follow these guidelines when using ig™ 5-alpha chemically competent cells.

  • Handle competent cells gently as they are highly sensitive to changes in temperature or mechanical lysis caused by pipetting.
  • Thaw competent cells on ice and transform cells immediately following thawing. After adding DNA, mix by tapping the tube gently. Do not mix cells by pipetting or vortexing.

Calculation of Transformation Efficiency

Transformation Efficiency (TE) is defined as the number of colony forming units (cfu) produced by
transforming 1µg of plasmid into a given volume of competent cells.

TE = Colonies/µg/Dilution

Transform 1 µl of (10 pg/µl) pUC19 control plasmid into 50 µl of cells, add 950 µl of Recovery Medium. Dilute
10 µl of this in 990 µl of Recovery Medium and plate 50 µl. Count the colonies on the plate the next day. If
you count 100 colonies, the TE is calculated as follows:

Colonies = 100
µg of DNA = 0.00001
Dilution = 50/1000 x 10/1000 = 0.0005
TE = 100/.00001/.0005 = 2.0×1010