PCR with radiactive nucleotides

Wed Nov 16 15:06:23 EST 1994


> We have been doing PCR with S35 nucleotides and have just found that
> the PCR block is heavily contaminated.  The manufacturer of the PCR
> says that S35 can go through the walls of the tube.  This is a little
> hard for me to believe.  I wonder if some tubes do not seal properly.
> In any case,  have other people had this problem and is there any
> way to avoid this type of contamination??

As it was already posted in the net, the S35 breaks down into a "hot" gas
which contaminates everything. What we've been doing to circumvent this
problem is to use thick walled PCR tubes (0.5 - kind of a pain regarding
mineral oil and handyness, but we've had no contaminations so far).
But, most importantly, the thermocycler should be kept in a hood, and all
tubes after the PCR is over should be there manipulated. As a matter of
fact, the sequencing gel is also run in the hood, but I think this is a
little too much ;-).

Hope this helps,

Reinaldo A. deBrito
Dept. Biology
Washington U.
St Louis, MO

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