The Calculation of Transformation Efficiency

Transformation efficiency (TE) is defined as the number of cfu (colony forming units) produced by 1 µg of plasmid DNA, the equation for calculating the number of transformant cfu (TC) is as follow:

And then the transformation efficiency (TE) is calculated according to the following equation:

In this study according to the methods, the dilution ratio for Inoue and CRM method was 5 × 10⁶ times, for CaCl₂ method was 1 × 10⁶ times. The dilution ratio for commercial competent cells was also calculated as 500,000 times in this study. For calculation of transformation efficiency, 2 μL (500 ng/μL) plasmid DNA was added in 100 μL competent cells, the plated volume was 50 μL. There are three repeats for each assay.