Frozen Section Protocol

1. Place the tissue in a small sealed box (if the tissue is too small, to hold it, pour in some embedding reagent like OCT);
2. Froze the box in liquid nitrogen (approximately 10-20s needed);
3. Transfer the tissue to frozen section machine or store at -80°C for future use;
4. Equilibrate at -20°C for approximately 15 minutes to prevent cracking of the tissue block when sectioning;
5. Section the block at a range of 6-8 µm and place on slides;
6. To help tissue adhere, air dry sections for a few minutes before fixing.

Advantages:

1. Frozen section nornally takes less time than paraffin section due to simpler procedures.
2. In frozen section process, the activity and epitope of target antigens can be well preserved compared to paraffin section, thus a antigen retrieval procedure is not usually needed in frozen section.

Disadvantages:

The tissue could be less morphologically interacted than paraffin section and antigen signals might be more dispersed in the final scope. The section slides might only be stored at low temperature like -80°C.