This material is from the 4th edition of The Zebrafish Book. The 5th edition is available in print and within the ZFIN Protocol Wiki.


OCT Embedding for Cryostat Sectioning of Embryos or Larvae

(Source: R.BreMiller)

1. Fix animals as desired.

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

3.Soak fixed fish in 30% sucrose until they sink.

4.Transfer fish to embedding chamber (plastic test tube stoppers or inverted Beem capsules whose tips have been cut off) filled with OCT cryostat embedding medium (Tissue Tek).

5.Freeze chamber by dipping it slowly and gradually into liquid N2.

6.Frozen blocks can be stored at -70C if they are wrapped well so that the tissue does not dehydrate.

7.Cut 10-20 µm sections on a cryostat at -20C, transfer them to subbed slides and let them dry completely.

8.Sections can be stored at -20C in a sealed slide box.

The Zebrafish Book