PCR with radioactive nucleotides

[ROSS at SCI.WFEB.EDU]

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??

					Alonzo Ross
					Worcester Foundation
					ROSS at SCI.WFEB.EDU