Hi Mark,

My only experience with radioactivity is using I125 for research purposes.  To maintain our radioactive license, we need to have several things in place for 'hot' materials to be brought into a particular lab.  In the past, I have processed hot material by hand & determined that no nucleotides leached into my processing solutions - thus disposal was normal.  I have discussed sectioning with our safety people, and have discovered that it will be complicated & cumbersome.  For example, you have to protect yourself with the proper barriers (leaded plexiglass, lead shields, etc) which makes it logistically tough (I use the large polycut microtomes, but I can imagine with a standard 'tome it'd be just as difficult).  Also, its my understanding that any equipment which is used for radioactive specimens, must be labeled as such, and safety will do contamination swipes around the lab, to be sure the hot material is maintained in the designated area.  If, while sectioning it is determi!
ned that the waste shavings are 
hot, then proper disposal is necessary.  However, (and this has not been tested in my lab) if the shavings, equipment are determined not to be hot - then it's not radioactive equipment or waste - but you still need to protect yourself if the blocks are hot.  In addition, you need documented, annual training to handle hot material.  If I ever do section and stain hot blocks, then I will need to test the radioactivity levels constantly, as we use various amounts depending on the study we are doing, and some are retained longer, depending on the surgical placement.  

Having said all this, it sounds like some of the nucleotides used for clinical patients are considered safe.  So it depends on what level of activity you are using.

Mary



>>> <mark.lewis@shandon.com> - 9/8/1999 5:15 PM >>>
Hello HistoNetters,

Does anyone out there  have any experience in processing tissues that have been labeled with radioactive isotopes?  If so, did you have to dispose of the processing reagents as radioactive waste?  I would think this would be the way to go, but I'm not experienced in this area and don't know all of the regulations concerning radioactive waste.

Any help on this subject will be appreciated.

Thanks

Mark Lewis
Technical Specialist
Shandon
1-800-245-6212 ext. 4013