Proper sample preparation is essential for successful lipid staining. Here are the general steps:
1. Fixation: Lipids can be lost during the fixation process, so it's crucial to choose a method that preserves lipid content. Formalin-free fixatives or freezing techniques are often preferred.
2. Sectioning: Tissues are usually cut into thin sections using a cryostat for frozen samples or a microtome for paraffin-embedded samples. Frozen sections are typically recommended for lipid staining to avoid lipid extraction during processing.
3. Staining: Apply the chosen lipid stain to the tissue sections. The staining protocol varies depending on the type of stain used. For example, Oil Red O requires the sections to be incubated in the dye solution, followed by a differentiation step in a solvent like isopropanol.
4. Mounting: After staining, sections are usually mounted using an aqueous mounting medium to preserve the lipid stain. Coverslipping is essential to protect the stained sections and facilitate microscopic examination.
