Transformation Efficiency Calculator

Calculate transformation efficiency for competent bacterial cells.

Transformation Data

Colonies Counted on Plate

Dilution Factor

DNA Amount Used

Volume Spread on Plate (uL)

Total Recovery Volume (uL)

Plasmid Size (bp)

1.50e+6

CFU / ug DNA

Moderately competent (10^6-10^7 CFU/ug)

Colonies on Plate150

Total Transformants15,000

DNA Used0.0100 ug

Colonies per ng DNA1.50e+3

DNA Molecules Used1.82e+9

Transformation Frequency1.50e-4

Ultra-competent: more than 10^9 CFU/ug (Stbl3, XL10-Gold)

Highly competent: 10^8-10^9 CFU/ug (DH5alpha, TOP10)

Standard: 10^7-10^8 CFU/ug (routine cloning)

Low: less than 10^6 CFU/ug (subcloning only)

Efficiency = (Colonies x Dilution x Total Vol / Plated Vol) / DNA (ug)