Cresyl Violet Staining of Tissue Sections: A Staining Procedure to Visualize Cartilage and Bones in Frozen Mouse Embryo Sections

To visualize cartilage and bone regions in a tissue section, begin with a glass slide carrying a thin frozen mouse embryo tissue section of interest.

Briefly thaw the cryosection and immerse it in suitable ethanol concentration to remove the cryo-embedding medium. The removal step helps prevent loosening of the medium, which may otherwise affect tissue visualization during staining. Additionally, ethanol fixes the tissue, maintaining tissue morphology and integrity.

Next, pipette a cresyl violet solution onto the tissue. Cresyl violet, a positively charged, basic dye, binds to polyanionic moieties such as proteoglycans in the cartilage tissue matrix. Whereas, in mineralized tissue such as bones, it reacts with negatively charged groups such as phosphate groups in the bone matrix.

Being a metachromatic dye, cresyl violet stains different regions of the tissue in colors different from the natural dye based on its interaction with different chemical constituents within those regions.

Now, wash the tissue in a suitable ethanol concentration to remove excess stain. Immerse the tissue in increasing ethanol concentrations to replace the water from the tissue, dehydrating the tissue. Wash the tissue with xylene to displace ethanol, making the tissue transparent for microscopy.

Under a light microscope, cartilage tissue appears magenta while the bone tissue appears brown, facilitating their differentiation from each other as well as the surrounding tissue.