Frozen Sections (Cryo-section)

Cryo-sectioning is a technique for cutting frozen tissue samples which are then collected on glass microscope slides. The tissue is rapidly frozen by floating the sample above liquid nitrogen. Samples are cut at temperatures ranging between -24o C to -28o C. The thickness we cut at depends on the researchers needs, from 16µm to 30 µm. For large tissue such as mouse brains or adult fish trunk, the sections are collected singly. Smaller tissues such as fish embryo, are embedded in an in-house blend of agar/agarose. The tissue is then sectioned and collected as ribbons of serial sections. This type of continuous serial sectioning was developed here in this Histology lab. With this technique, we can cut the whole tissues serially without losing any tissue. Depending on the researchers’ requirement, we could put over a 100 sections on a slide. See image 1.

Routinely sectioned tissues:

  • Adult mouse brain and heart                         
  • Whole embryonic mouse
  • Adult zebrafish trunk, and gonads
  • Stickleback fish trunk, lower jaw and gonads
  • Embryonic zebrafish and stickleback fish
  • Anemone
  • Fruit fly                                            


Text Box: Image 1. Cryo-section of 4 different age embryos embedded in agar/agarose. Slide showing 4 rows of 13 sections after Immuno-staining (IHC)



We can accept samples in fixative or 30% sucrose. We will process, embed and section as per researchers need. If the client want to embed their own tissue, it is best to contact the director of Histology as to the best way to embed the tissue. This helps to ensure top quality sections.

To submit samples for cryo-sectioning, the researcher will need to consult the Director of Histology to find an open time slot, as times for cryo-sectioning are limited. A one page form must be filled out before samples can be accepted and cryo-sectioned. The information needed to complete the form is how the researcher would like their samples to be sectioned, what kind of slides they would like to be used, any special instructions regarding the sample, account number and contact information. It is very important to talk to the Director of Histology beforehand and fill out the form. If not, samples cannot be processed or sectioned.