Transformation Efficiency
Dima Klenchin
klenchin at facstaff.REMOVE_TO_REPLY.wisc.edu
Thu Mar 18 13:43:59 EST 1999
:Hi all,
::I am transforming CaCl competent cells and would be grateful if anyone could
: tell me, or
:point me in the right direction on, how to calculate the transformation
: efficiency of my
:cells. I am/may be foced to blunt end ligate and therefore want cells with a
: high
:transformation efficiency. Our copy of Current Protocols in Molecular Biology
: is missing
:the vital pages.
You have used, say, 10 ng of DNA per tube. After dilution with medium and
growth for one hour you have, say, 1 ml. You plated 50 ul of this on the
plate. You've got, say, 100 colonies. The transformation efficiency is
how much colonies you would get if you'd used 1 ug DNA and plated all
your transformed bacteria (for this calculation it is assumed that
dependence on [DNA] is linear, which is generally incorrect)
In the above example it is 100*20/0.01=2*10^5/ug
- Dima
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