DNA Contamination in PCRs

Dr. Duncan Clark Duncan at genesys.demon.co.uk
Wed Jun 23 13:59:59 EST 1993


In article <0096E6BC.E8B032E0.27546 at hal.hahnemann.edu> farleyp at HAL.HAHNEMANN.EDU writes:

>
>Another lab was describing problems they have encountered in PCR where their
>negative controls are giving positive signals -- contaminated reagents!  I
>suggested that they aliquot all fresh reagents and never use the same source
>twice.  In addition, they have also been using plugged pipette tips.  I think  
>this should work well, but they were wondering how reagents could be treated   
>(apart from autoclaving) that may eliminate contamination.  They have already  
>spent a fair amount of money on new reagents for RT-PCR and would like to know 
>if they could use some method such as UV irradiation, etc.  Does anyone know
>any specific procedures?
>
>Thanks in advance for any suggestions you might have.
>
>Sincerely,
>
>Patrick Farley
>farleyp at HAL.Hahnemann.edu
>  
>
If the group is amplifying 16s or 23S rRNA genes then beware of amplifying DNA
present in the taq pol itself. I've seen reports of 10 genome copies per 2.5u
taq pol. I'm sure there has been a recent paper on this in Journal of Clinical 
Microbiology within the last two months or so. 

Duncan

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