Re: Voltility of S35 compounds

[pcharp@ix.netcom.com (Paul A. Charp )]

Although I have not performed the experiment you discuss, I have used 
S-35 labeled amino acids in protein synthesis assays.  I would be 
surprised if the S-35 moiety would become airborne (gaseous sulfur 
dioxide?) under normal circumstances.  However, I would caution the PI 
with the following:  1)during centrifugation, be sure all tubes are 
balanced as closely as possible.  Any failure can result in aerosols 
and inhalation; 2)wait until centrifuge comes to a complete stop if the 
procedure is not performed in an interlocked system 3) if a vacuum 
system is necessary (ultracentrifugation), monitor exhaust area with 
typical survey meter.  4) upon completion - surface swipes of 
centrifuge interior and, if possible, vacuum system (traps, etc.).

Of course, a brief safety lecture on proper isotope handling and lab 
safety procedures is a given.

paul charp (pcharp@ix.netcom.com)

You wrote: 
>
>Hi,
>
>One of my Principal Investigators asked if there is a problem with
>inhalation of S35 under the following conditions:
>
>Experiment:  charging of native tRNAs using S35 cycteine as tracer,
>extract of E. coli (S100 fraction) as source of charging enzymes, 
yeast
>tRNAs added.  Incubation for 15 minutes at 37 C required.
>
>This experiment would be difficult by not impossible to be performed 
in a hood.
>
>Has anyone had experiance with this type experiment?  The PI is 
worried
>about exposure to her undergrads.
>
>Thanks for your help.
>
>Denny
>Carnegie Mellon University
>dr4i@andrew.cmu.edu
>412-268-3221
>