Re: in situ

I'm not a histologist, but have been grateful for generous advice from many of you in Histonet, & am happy to finally have a chance to reciprocate in small part with some thoughts on ISH, which I use: Radiolabeled probes are still the only really quantitative measure (and technically only semi-quantitative at that), so while there's some effort involved in getting clearance for use of radioactivity, it's worth it if you need quantitation. The small amount of 35S involved is about as innocuous as radioactivity gets. If "all-or-none" label is all you need, non-radioactive probes can work well. Designing probes is far from trivial, but with any luck you can find a published probe sequence and have some of that made up commercially. (One company I've had good experience with is "Oligo's Etc." in Wilsonville, OR. A lifetime supply of a 48-mer oligoprobe is ~ $150). Riboprobes tend to be more sensitive but require more sophisticated facilities to produce, and oligo's are easier & can work quite well. I don't know whether you can travel to a course, but National Institutes of Health (Bethesda, MD) frequently offer excellent week-long courses through the Foundation for Advanced Education in the Sciences (check under Training Opportunities in www.nih.gov). If it's any reassurance, ISH is really a relatively cheap & forgiving technique, and very versatile, as "high tech" methods go. For example, published parameters for a 48mer oligo assay are pretty well optimized already for most other 48mer oligos. I've had many high school and college students master it quite readily. I'd be happy to try to answer specific questions if you have any--I owe you folks! Good luck, Susan Bachus, George Mason University