cDNA cloning

[Tracey Smith]

We have been trying to clone cDNA into either the T7 Select vector or 
Stratagene's Lambda Zap vector.  Regardless of the cDNA or the 
adapters that we use, we consistantly only clone adapters and no 
cDNA.  We have used several types of column chromatography and NH4OAC 
precipitations to try and clean the free adapters from our cDNA.  
Even when we use our column chromatography and select fractions 
that should contain only large DNA (>800bp), we will still only get 
free adapters cloning.  Has anyone else experienced this problem and 
if so....how do you effectively get rid of all of those adapters?