Protocol for the Preparation of Gelatin-coated Slides for Histological Tissue Sections
In order for tissue sections to be retained on histological slides during staining and washing steps, slides need to be coated with adhesive compounds. Although there are a variety of such compounds, gelatin is the most frequently used for histological purposes.
Please read the protocol in its entirety before starting.
- Gelatin-coating solution: 1 L deionized H2O, 5 g gelatin, 0.5 g chromium potassium sulfate dodecahydrate CrK(SO4)2 · 12H2O
- Filter units
- Histological slides
- Hot plate with magnetic stirrer
- Slide racks
- Staining dish
- Prepare the gelatin-coating solution by dissolving 5 g of gelatin in 1 L of heated, deionized H2O (temperature should not exceed 45 °C).
- After the gelatin has dissolved, add 0.5 g of chromium potassium sulfate dodecahydrate. Chromium potassium sulfate dodecahydrate will positively charge the slides allowing them to attract negatively charged tissue sections.
- Filter this solution and store at 2-8 °C until use. It is recommended that this solution be filtered again immediately before use (adjust to room temperature before filtration).
- Place the histological slides into metal racks.
Note: The slides should be cleaned by washing them in soapy water and rinsing them thoroughly, first in tap water and finally in deionized water.
- Dip the racks containing the slides 3 to 5 times (~5 seconds each) into the gelatin-coating solution.
- Remove the racks containing the slides and let them drain. Blot excess solution from the racks onto filter paper (gently tap the racks against the filter paper for better drainage).
- Place the racks containing the slides on the lab bench and cover them with paper towels to protect them from dust.
- Dry at room temperature for 48 hours.
- Dried slides can be put back into the boxes that they arrived in and stored at room temperature until use. Slides intended for cryostat sections can be stored at -20 °C.