The stain shown in the image is most likely which histochemical technique?

• A. Bielschowski
• B. Ziehl-Neelsen
• C. Gram
• D. PAS

Answer: (A)

Silver-based neural staining highlights nerve fibers by depositing silver onto neurofilaments, giving a distinctive dark appearance to axons and neurofibrils against a lighter background. Bielschowsky’s method is a classic example of this approach, specifically designed to visualize fine neural processes and neurofibrils in tissue. If the image shows slender dark threads tracing through the tissue, that pattern is characteristic of Bielschowski staining. In contrast, Ziehl-Neelsen reveals acid-fast organisms as red/pink bacteria, Gram stains color bacteria purple or pink, and PAS marks carbohydrates such as glycogen, mucin, or basement membranes in magenta. So the dark neural fibers point to the Bielschowski silver staining technique.