Collagen cannot be expected to stain uniformly throughout, since "collagen" is a blanket term for at least 10 different chemical substances; therefore, certain areas of the collagen will take on the dye with different intensity. I like the comments made by Geoff about fixation and removing the paraffin, which I'm sure you've already addressed. His comment about not drawing any conclusions about the collage through the use of special stains is important. If the investigator is not satisfied with the standard collagen stains using analine blue, fast green, or acid fuchsin, then they might want to try some IHC or tapping-mode atomic force microscopy to further identify the subtypes of the collegen.
Keith M. Mikoff HTL/HT(ASCP) _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet