An argyrophil III method for the demonstration of micro- and oligodendroglia.

Micro- and oligodendroglia, plasma and nucleoli of nerve cells, capillary wall and nuclei of astrocytes become visible when sections of formol fixed human brain are immersed, without any previous treatment, into a physical developer of pH 10.5. The staining is inhibited by the catalytic activity of the tissue elements involved. By means of pretreatments with 1% performic acid and 30% sodium rhodanide dissolved in 0.4% sodium hydroxide, the catalytic activity in the unwanted tissue elements is suppressed, and this results in an elective demonstration of micro- and oligodendroglia. Reducing groups of the tissue or any kind of performed nuclei play no role in this silver staining.