Glial fibers are stained blue by which stain?

• A. Phosphotungstic acid-hematoxylin
• B. Luxol fast blue
• C. Cresyl echt violet
• D. Gold sublimate

Answer: (A)

Phosphotungstic acid-hematoxylin highlights fibrillar elements in neural tissue, including glial processes, by forming a blue compound with the filamentous components. This makes glial fibers stand out as blue against the surrounding tissue. Luxol fast blue mainly stains myelin, giving blue for myelin sheaths rather than the glial filament network. Cresyl echt violet targets Nissl substance in neuronal cell bodies and does not color glial fibers blue. Gold sublimate is a silver-based method used for other fiber systems and does not selectively stain glial fibers blue.