Intact Genomics Electroporation Competent Lactococcus lactis Cells are customer strains optimized for the highest transformation efficiencies which is ideal for applications requiring high transformation efficiencies, such as with cDNA or gDNA library construction. Lactococcus lactis MG1363 is the Plasmid-free derivative of L. lactis strain SH4109.
Competent cell type: Electrocompetent
Species: L. lactis
Strain: IL 1403 or MG1363
Transformation efficiency: ≥ 1 x 106 cfu/µg pNZ8148 DNA
Blue/white screening: No
Shipping condition: Dry ice
Reagents Needed for One Reaction
ElectroCompetent Lactococcus lactis Cells : 25 µl
DNA (or pNZ8148 Control, 50 ng/µl): 1 µl
Recovery medium: 1 ml
ElectroCompetent Lactococcus lactis Cells : -80 ºC
pNZ8148 control DNA: -20 ºC
Recovery medium: 4 ºC
Transformation efficiency is tested by using the pNZ8148 control DNA supplied with the kit and using the protocol in this manual. Transformation efficiency should be ≥1 x 106 CFU/µg pNZ8148 DNA. Untransformed cells are tested for appropriate antibiotic sensitivity.
Follow these guidelines when using Electroporation Competent Lactococcus lactis 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.
Note: A high-voltage electroporation apparatus such as Bio-Rad Gene Pulser II #165-2105, capable of generating field strengths of 16 kV/cm is required.
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 (50 ng/µl) pNZ8148 control plasmid into 25 µl of cells, add 974 µl of Recovery Medium. Dilute 100 µl of this in 900 µl of Recovery Medium and plate 50 µl. Count the colonies on the plate in two days. If you count 300 colonies, the TE is calculated as follows:
Colonies = 300
µg of DNA = 0.05
Dilution = 50/1000 x 100/1000 = 0.005
TE = 300/.05/.005 = 1.2×106