Which tissue is used as the control slide for Bielschowsky's Silver Technique?

• A. Grey matter
• B. Spleen or liver
• C. Aorta or skin
• D. Infected tissue

Answer: (A)

Grey matter is used as the control slide because Bielschowsky's Silver Technique highlights neural elements—neurofibrils and nerve fibers—in nervous tissue. Grey matter contains abundant neuronal cell bodies and dense neuropil with neurofibrils, so it should take up the silver stain clearly, confirming the staining process is working properly. Tissues like spleen or liver, aorta or skin, or infected tissue do not contain those neural structures in the same context, so they wouldn’t provide a reliable positive reference for this stain.