Victor,
We are experiencing some of the same problems of tissue adhesion on
+charged slides.  We think that we are working with very positively
charged tissue (collagen, cartilage, meniscus) and that the + slides
which are designed for use with most other tissues which are
negatively charged are not good for positively charged tissues.  What
we think we need are negatively charged slides.  Does anyone know how
we could make some negatively charged slides?  Are plain untreated
slides negatively charged?
Patsy Ruegg