Calculation of Transformation Efficiency

I need help with this transformation efficiency problem:

You add 10 ng of pGEM to 50 ul of competent cells, and then dilute this into a total of 1 ml Luria broth after the transformation. You take 100 ul of the Luria broth and plate on and agar plate. The next day, there are 780 colonies on the plate. What was the transformation efficiency?

Thanks.

Solution Summary

This question describes a problem that is often encountered in microbiology labs. This solution describes how the transformation efficiency is calculated for competent cells using a typical plasmid. The values given in this problem can also be substituted with other values so that the solution can be applied to similar problems. There is also a link provided for further reading on bacterial transformation. Something very useful for writing lab reports on the subject.