Hi Amos

No need t be sorry if you don't like our Bunsen burner idea. I would
probably have shown a similiar reaction if someone had come up with the idea
before we had gone through endless experimenting with waterbaths. Even in
closed Coplin jars with a thermometer hole in the lid and a completely
covered waterbath we had tremendous trouble in getting the temperature
inside the Coplin jar back to >= 95 C once we inserted the slides (we are
not at 6000 ft as is Louise, but close to 2000 ft). As it took aeons to get
back to 95 C (and I started to worry about the influence of the time till
you reach 95 C again) and was very hard, if at all possible, to keep the
temp. >= 95 C, we finally opted for the Bunsen burner. With respect to  your
concerns about even distribution of the temperature inside the beaker and
temperature fluctuation in the process of regulating the heat with a Bunsen
burner, there was quite some experimenting addressing these issues as well.
Without going into details, I believe we have a protocol now that can
deliver far more consistent results than we would ever have got with a
waterbath. We have far less temperature fluctuation than we would have with
a waterbath where we can barely maintain 95 C inside a Coplin jar over 40
min. In addition, a control block (12 tumors, 3 each with a score of 0, 1,
2, and 3) that goes with every test allows us to check for pretreatment
problems  -  and I can tell you, it stains like a charm, test after test.

Andi Kappeler
Institute of Pathology, University of Bern, Switzerland