Staining Methods for Normal and Regenerative Myelin in the Nervous System

Histochemical and fluorescence-based techniques enable the specific identification of myelin by bright-field or fluorescence microscopy. In this chapter, we describe four histological methods for the evaluation of myelin on peripheral nerve tissue sections. The first method combines the Luxol fast blue (LFB) technique with a modified Picrosirius staining contrasted with Harris hematoxylin, called MCOLL. This method simultaneously stains myelin, collagen fibers, and cell nuclei, thus giving an integrated overview of the histology, collagen network, and myelin content of the tissue in paraffin-embedded or cryosectioned samples. Secondly, we describe the osmium tetroxide method, which provides a permanent positive reaction for myelin as well as other lipids present in the tissue. The third method is the immunofluorescence-based detection of myelin proteins that allows to combine information about their expression status with other proteins of interest. Finally, the FluoroMyelin™ stains enable a fast detection of the myelin content that can be easily implemented in immunofluorescence staining panels for cryosectioned tissues. Together, this chapter provides a variety of methods to accurately identify myelin in different experimental approaches.