Paraffin sections of nervous tissue supravitally stained with methylene blue: a new, reliable and simple fixation technique.

Two steps are recommended for fixation of central nervous tissue after supravital staining with methylene blue: application of ammonium heptamolybdate followed by a paraformaldehyde-glutaraldehyde mixture. The two fixatives complement each other so that both dye and tissue are optimally fixed. Molybdate renders the dye water and alcohol insoluble, the aldehyde mixture conditions the tissue for embedding in paraffin. This technique is a suitable alternative to conventional whole mount and frozen sectioning methods.