Gelatin Embedding For Vibratome Sectioning Of Embryos Or Larvae

(Source: R. BreMiller from Zebrafish Book 5th Edition)

1. Fix fish as desired.

2. Wash in fix buffer, 3 times for 5 minutes each wash.

3. Soak fish in 0.3 M sucrose for at least 30 minutes. Remove yolk sac from fish with forceps.

4. Transfer fish with as little sucrose solution as possible into 17% gelatin in 10% Hank's saline at 37°C.

5. Swirl the fish to coat it well with gelatin and transfer it with a drop of gelatin onto a 5 mm square piece of glass made by scoring and breaking a clean microscope slide.

6. Orient the animal under a dissecting microscope with fine wire or forceps. The process may be facilitated by warming or cooling the glass plate.

7. Fasten the plate to a vibratome chuck with cyanoacrylic glue and clamp the chuck in the vibratome.

8. Surround the tissue with cold 0.3 M sucrose. Use frozen cubes of sucrose to maintain the temperature.

9. Sections can be cut 25-40 μm thick with this technique. Pick them up with brush and transfer to cold, subbed slides.

10. Remove excess sucrose with a Kimwipe and allow the slides to dry. They should be processed within a few hours.