ylzhao

我也常遇到类似的问题，顺便剪下一点供你参考。
Xylene in paraffin as a cause.  I had an interesting thing
     happen to me once. I worked Saturdays for a while, training a
     girl at another lab in Histotechnique. The first Saturday we
     cut, most sections floated to varying degrees, even things like
     tonsil. The tonsil cut very nicely and seemed well processed.
     Well, I was supposed to be the person in the know and I was
     stumped. Took me a while but I finally figured out that they
     didn't change the processors very often and there was lots of
     xylene in the paraffin, and I mean lots. Apparently this was
     the problem, because after changing everything and rotating on
     a regular basis the problem went away. I just thought I would
     throw that story in - because this experienced histotech didn't
     realize that excess xylene in the paraffin could cause problems
     with adhesion of sections.