Submitting tissue for frozen sections

Size of specimens:

1. Tissue should be trimmed to specified region before bringing to lab.
2. Clean off all fat.
3. Size to fit embedding molds.
4. If cross sections are needed do not have tissue too long.

Preparation of tissue:

1. Freeze fresh frozen tissue immediately in liquid Nitrogen (tubes or vials).
2. If embedding is done in OCT do not put back in liquid Nitrogen.
3. Frozen tissue can be stored in 80° freezer but transport to lab in liquid nitrogen or on dry ice only. DO NOT use crushed ice.

Acceptable fixative:

1. 4% Paraformaldehyde (PFA) – place tissue in fixative immediately.
2. Fixation times will vary. For example:
   small lymph node/mouse ovary – 2-3 days
   pancreas/lung/kidney/etc. – 5 days
   Fix mouse testis in PFA for 2 days, cut in half and fix for 2-3 weeks or more.
3. We will provide 30% sucrose to cryoprotect tissue (sucrose made in PBS Buffer pH 7.2 – 7.3).

Frozen sections:

1. Tissues will be cut at 5 – 6 microns
2. Two sections per slide unless otherwise specified.
3. Sections are placed on superfrost/plus slides (charged).

Slide boxes:

Slide boxes need to be brought to the lab with tissue or will be provided at a charge of $5.00 each.

You must bring dry ice when picking up frozen tissue and prepared slides.

You need to enter a service request in iLab (Research Histology Core) under Cryo Sections