What stain is used to visualize Nissl granules?

Cresyl fast violet is specifically used to visualize Nissl granules, which are comprised of ribosomal RNA and are found in the rough endoplasmic reticulum of neuronal cells. This stain binds to the RNA within the Nissl bodies, allowing for the identification of neuronal cell bodies and the assessment of neuronal health and morphology.

In the context of histology and neuropathology, this stain is particularly valuable for highlighting the distribution and density of neurons in various states of health and disease, aiding in the diagnosis of neurodegenerative disorders. The specificity of cresyl fast violet for Nissl bodies makes it the preferred choice for examining neuronal structures in tissue samples.

Other stains listed serve different purposes and are not effective for visualizing Nissl granules. For instance, Luxol fast blue is primarily used for myelin, Grocott's methenamine silver is used to stain fungi and certain bacteria, and rapid giemsa stain is often utilized for blood smears and cytological preparations rather than for targeting the Nissl substance in neurons.