When I treated a cDNA (library) with XhoI, the sesult on the gel looked,
as if the cDNA smear shifted to a HIGHER molecular wheight.
cDNA 1st strand synth was performed using methylated dCTP, so XhoI (MBI,
Fermentas) should cut only in the site provided with the
oligo-dT-primer. The aim is an unidirectional cDNA library. Genomic DNA
was not visible in the poly-A RNA used.
Has anyone of you an idea?