Product Description
The E. coli Competent Cells are prepared according to a modified procedure of Hanahan (1). Competent cells can be used for many standard molecular biology applications. C25108 competent cells are available for convenient transformation in two efficiencies: High Efficiency at greater than 108cfu/µg and Subcloning Efficiency at greater than 107cfu/µg. C25108 competent cells are available in high efficiency at greater than 108cfu/µg.
Storage Conditions: -800C, thaw on ice when ready for use. Do not refreeze thawed, unused aliquots.
Shelf life: 24 months
Competent cells, supplied in 200µl aliquots. Typically, 100µl of competent cells are required for a standard transformation.
For the competent cells supplied in 50µl aliquots, transformation can be completed in the tube in which the cells are supplied.
Testing parameters:
Antibiotic Sensitivity (Ampicillin) - 15 µl of untransformed C25108 Competent E. coli (High Efficiency) streaked onto a Rich Broth plate containing Ampicillin will not form colonies after incubation for 16 hours at 37°C.
Antibiotic Sensitivity (Kanamycin) - 15 µl of untransformed C25108 Competent E. coli (High Efficiency) streaked onto a Rich Broth plate containing Kanamycin will not form colonies after incubation for 16 hours at 37°C.
Antibiotic Sensitivity (Streptomycin) - 15 µl of untransformed C25108 Competent E. coli (High Efficiency) streaked onto a Rich Broth plate containing Streptomycin will not form colonies after incubation for 16 hours at 37°C.
Antibiotic Sensitivity (Tetracycline) - 15 µl of untransformed C25108 Competent E. coli (High Efficiency) streaked onto a Rich Broth plate containing Tetracycline will not form colonies after incubation for 16 hours at 37°C.
Transformation Efficiency - 1 well of C25108 Competent E. coli (High Efficiency) cells were transformed with 100 pg of pUC19 DNA using the transformation protocol provided. Incubation overnight on LB-Ampicillin plates at 37°C resulted in >1 x 10e8 cfu/µg of DNA.
Calculation of Transformation Efficiency (Colony Forming Units [cfu])
Transformation efficiency is defined as the number of colony forming units (cfu) produced by 1µg of Competent Cells Control DNA (supercoiled plasmid DNA) and is measured by performing a control transformation reaction using a known quantity of DNA, typically 0.1ng, then calculating the number of cfu formed per microgram of DNA.
