PCR primer storage?

[qhuang]

In article <c22e31f9.0203260346.5605154c at posting.google.com>, 
bonehammer73 at yahoo.com says...
> acoustic52 at hotmail.com (NM) wrote in message news:<410c9a77.0203231709.1f72b270 at posting.google.com>...
> > What is the best diluent to use to dilute PCR primers? ANy
> > advantage/disadvantage to storing them at -70??
> 
> To simplify our lives, in my lab we prefer not to add any salt to the
> PCR other than those already present in the PCR 10x buffer. Thus, to
> dilute primers, we use distillated, autoclaved water and make small
> 100 uM aliquots ("mothers").
> From these, we prepare 25 uM working solutions, also using distillated
> water. Mothers can be kept at -70 with no problem whatsoever, working
> solutions go together with the rest of PCR reagents at -20 (*far away*
> from the DNA)
> 
> HTH
> 
> Chiara Martellossi
> 
In our lab, the stock primer is 400uM, and work primer is 10uM. For every 
25 volumn PCR reaction, we use 0.3ul per single PCR. BTW, we use the 
distillated, autocaved water to resolve the primer powder after being 
gotten from the company. The stock one is stored in -80 degree frig, and 
work one in -20 degree frig.