Need hep with Cos-7 transfection

[Matthew Kennedy]

Has anyone used TransIT LT-1 to transfect Cos-7.  I had great success for
a couple of months using it and recently experienced an aproximate 10 fold
decrease in tranfection efficiency, based on immunoflourescence(ie still
high expression in each cell just not as many transfected).  I had been
using 2µl LT-1/ug DNA and  5µg DNA/100mm dish.  I cannot attribute it to
type of DNA prep, old passage of cells or cell density.  Now I use 3µl
LT-1/µg DNA and I am still not getting very good efficiency which I need
for biochemical studies.  Any info regarding this method specifically or
Cos-7 transfection in general would be useful.
Thanks
Matt Kennedy

-- 
Matthew E. Kennedy PhD
Research Fellow
Mayo Foundation
Rochester MN     
--"The opinions expressed within are mine and mine only"--

-- 
Matthew E. Kennedy PhD
Research Fellow
Mayo Foundation
Rochester MN     
--"The opinions expressed within are mine and mine only"--