A simplified technique for histologic analysis of central nervous system tissues using glycol-methacrylate plastic coupled with pre-embedding immunocytochemistry

Paraffin and some plastic embedding techniques will destroy many antigens routinely detected by immunocytochemistry performed on frozen tissue sections. However, morphologic quality is compromised to varying extents in frozen tissue, even with the use of cryoprotection. We report a simple glycol-methacrylate (GMA) embedding technique using vibratome-sectioned mouse brain reacted for tyrosine hydroxylase (TH) immunoreactivity before plastic embedding. In this study we used a short (4 h) simple, GMA embedding procedure which subsequently provided 1.5–5.0 μm sections yielding morphologic details superior to frozen or paraffin sections. Prior to embedding we used a peroxidase-antiperoxidase (PAP) reaction with the 3,3′ diaminobenzidine tetrahydrochloride (DAB) chromogen visualizing TH. Several different counterstains were used, demonstrating the versatility of this embedding procedure.