We've been using the mutagenesis kit marketed by Amersham for some time now.
Recently, they began marketing a new "improved" version. The old version used
Klenow for extension of a primer and 16 degree overnight extension/ligations;
the new kit uses T7 polyermase and 37 degree 30 minute extension/ligation.
The old kit used nitrocellulose filtration to remove unreacted DNA; the new
one uses t5 exo; there are a couple of other differences.
My main question is if anyone has also had experience with both versions, and
whether they have noticed that the overall frequency of mutagenesis, as well
as the "quality" of the reactions as judged by gel analysis of samples seems
to be worse for the newer version?