HELP: PLASMIDS & Transfromation

rogers elizabeth erogers at umbc.edu
Tue Feb 7 15:05:56 EST 1995


I too have had some trouble with competent cells from BRL, though I was 
using Electromax cells.  Sometimes I'd use the LE DH5a cells at the same 
time and get transformants with the same DNA. I think my problem was in 
DNA concentration since a lot of my ligations tend to give low yields of 
desired product, so I generally used more DNA than called for in the 
protocol.  Sometimes diluted DNA worked better, sometimes not.  I never 
got consistent results in terms of transformants per ug of DNA, but never 
really had the time to troubleshoot the whole process.  I tried to use 
cells never thawed to make sure that was not the problem. Usually when I 
ran positive controls they would work, but I only ran them after I had a 
problem. Hope this helps.

Beth 



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