Question: What does BSA do in PCR reactions?

[Rick Conrad]

kang at msvax.mssm.edu wrote:
>
> In article <3j093q$3g3 at hydra.acs.ttu.edu>, Z3C20 at ttacs3.ttu.edu (Yi, Xiaoming) writes:
> >In <3iv5d5$nq5 at gensva.athena.livjm.ac.uk> M.Willcox at livjm.ac.uk writes:
> >
> >> Hello,
> >> 
> >> Could someone please tell me what BSA does in PCR reactions?
> >> 
> >> Many thanks,
> >> 
> >> Mark
> >
> >I think BSA can stabilize the enzyme(Taq), BSA is also added to restriction
> >enzyme digestions to stabilize the enzymes, since adding BSA will increase the total
> >concentration of protein in the mixture 
> 
> 
> I want to add another feature of BSA.
> In addition to stabilizing ptrotein by making high concentration of protein,
> BSA will bind and trap the trace amount of SDS which is contaminated into the
> reaction system in anyway.
> 
> SDS is a very very potent inhibitor of REs or Taq.
> 
> Good Luck.
> 
Just to add one more followup.  The "SDS sop" is possible, but the BSA
also serves as a general competitor for things which bind to the Taq
protein, such as the vessel wall.  We use 0.05% Triton-X100 instead and 
it works great.  The stabilization aspect has been overrated -- usually
its function in this regard is to serve as a competitor for proteases.