On Apr 3, 2:02 am, WS <novalidaddr... from nurfuerspam.de> wrote:
> Dear SiLin,
>> total ionic strength doesn't differ so much. It's most likely due to
> patent and other legal issues and/or due to the composition of the Taq
> storage buffer that the PCR buffers differ in composition. Seems that
> in real life these differences do not affect Taq much but of course
> require you to optimise a PCR for each polymerase/buffer composition.
> (another way nasty companies annoy scientists to stay with their
> products).
>> Furthermore, (that's my personal explanation for the ammonium salts)
> some Taqs are hot start and reversibly blocked (by imino group
> formation with eg lysines) with formaldehyde (btw, thats how some
> people make their homebrew hot start Taq, too). This formaldehyde -
> once liberated by heat- can be caught by the excess of ammonium ions
> and thus won't afftect the Taq anymore.
>> Best regards,
>> Wo
Hi,
Check the bible
http://info.med.yale.edu/genetics/ward/tavi/p06.htmlhttp://info.med.yale.edu/genetics/ward/tavi/p07.html
check also the references
From my own experience I can say that KCl-based buffers are far
superior than (NH4)2SO4-based ones in terms of PCR sensitivity, and
specificity (maybe because the latter ones require far more Mg2+ which
leads to unspecific amplifications)
