ligation

[R Hanemaaijer]

Does anybody know how to improve the efficiency of ligation?
We make cDNA libraries of immunoglobulin light and heavy chain cDNAs, 
and one of the steps with a (very) low efficiency is the ligation 
(0.1%).
We use the GIBCO-BRL ligase and buffermix. The ligation is with 
sticky ends, and is carried out at 15 degrees Celcius overnight. The 
mixture is then precipitated with ethanol and transformation is 
carried out by electroporation.
Thanks,

Roeland Hanemaaijer
R.hanemaaijer at pg.tno.nl