LEARNING ABOUT TRUTH AND BIASES THROUGH EXPERIENCE - SECTION SURFACE CORRUGATION, PROTEIN DENATURATION, AND STAINING

By developing and investigating the use of thin resin sections for ele ctron microscopy, we discovered that many of the current biases became invalid: 1) No evidence could be produced that the involved organic l iquids produce the protein denaturation responsible for loss of antige nicity and lowered resolution. Far immunolabeling, ''water-soluble'' r esins are not per se to be preferred over less polar and more hydropho bic ones. 2) The relief formed by the corrugated section surface enabl es access to the antigenic sites. The depth of relief is determined by the strength of copolymerization and depends on temperature, the chem ical nature of resin and biological matter, and, thus, also on surface modification through fixatives. The stronger the relief, the better t he immunolabeling and the less the image resolution. Strong copolymeri zation favors flatter relief, but also a hiding of antigenic sites by thin layers of resin. 3) Heavy metal stain remains the main culprit fo r low resolution of sections when compared to results obtained with ot her preparation methods. Microsc. Res. Tech. 42:33-42, 1998. (C) 1998 Wiley-Liss, Inc.