How do you mix PCR reactions - swish, flick or nothing? - (Mar/28/2005 )
hi all,
i usually vortex and briefly spin the tubes, so far this technique works well.
When all reagents are added few finger flicks enough, also, I tried to add all reaction mixture ingredients and don not mix at all, at least I did it in mine previous lab.
In new lab, where I just started working, people spin tubes for few seconds for PCR.
I tried all ways, either of them worked.
what i do is vortex the master mix and then aliquote the required amount in tubes. Then i add DNA to the PCR tubes and then flick the tubes. Vortexing at the DNA stage may be problematic in case when template is either Genomic DNA or high molecular weight plasmid.
Best wishes
Amit 
I agree. Its not a good idea to vortex as it might lead to shearing of your template and hence get nonspecific products. So flicking difinitely is a good solution but you can also mix by mild pipetting once or twice.
Simon
i usually vortex and briefly spin the tubes, so far this technique works well.
Hi,
Wt l do is first l add DNA and then master mix or individually Taq, buffer MgCl2 elc., to it. Then tap the tube with ur fingers anr then give a spin.
it is because to avoid the ppt of DNA while give a spin. It give a good result for year in my work 
Bye
I heard it's not good to vortex DNA and to pipet U & D enzymes... so flicking looks to me like the best solution.
Simon
Actually DNA that is sheared a bit works much better in PCR as there is less secondary structure
i usually don't vortex....prefer to spin it down for a short while...
Hai,
I belive in gentle pipetting for PCR mix.Its working fine for me.
Someone who does not mix their PCR master mix in any way is not a competent molecular biologist and should not be publishing papers.
-Matt