Preferential histochemical staining of protoplasmic and fibrous astrocytes in rat CNS with GFAP antibodies using different fixatives

Abstract

Serial sections of rat brain and spinal cord were fixed in either acid-alcohol or 4% paraformaldehyde, and stained for visualization of astrocytes using GFAP antibodies. With paraformaldehyde, GFAP-positive astrocytes were visualized almost exclusively in the grey matter of all above tissues. In sharp contrast, acid-alcohol treatment gave intensely stained GFAP-containing astrocytes in the white matter. Since fibrous astrocytes are mainly located in the white matter and protoplasmic astrocytes are located in the grey matter, it is concluded that acid-alcohol is a good fixative for fibrous astrocytes while paraformaldehyde is a better fixative for protoplasmic astrocytes.