1) My dropout plates won't gel. Check the pH. Standard dropout mixtures
are very acid and can lower the pH below the point where agar gels (or
maybe it's being hydrolyzsed in the autoclave...). At any rate I can
always tell when I forget to add the NaOH to my dropout plates (which is
more frequently than I care to mention) because that's what happens.
2) Cryptopleurine. As far as I know, there is no commercial source of
crytpopleurine anywhere in the world today. Call Jeff Strathern at the
National Cancer Institute branch at Fort Deitrich in Frederick, MD for an
amusing story about why. Apparently it can be made only from a plant that
grows in Australia and making it is such an unpleasant experience that no
one will do it more than once.
lichten at helix.nih.gov