Dec 08, 2025
Tissue Blocking Protocol for OCT Embedding - University of Minnesota TMCs
- BLS Histology1
- 1Clinical and Translational Science Institute, University of Minnesota, Minneapolis, MN
- Cellular Senescence Network (SenNet) Method Development Community
Protocol Citation: BLS Histology 2025. Tissue Blocking Protocol for OCT Embedding - University of Minnesota TMCs. protocols.io https://dx.doi.org/10.17504/protocols.io.kxygx4rpzl8j/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: December 08, 2025
Last Modified: December 08, 2025
Protocol Integer ID: 234508
Keywords: tissue blocking protocol for oct embedding, frozen tissue sample into optimal cutting temperature, tissue blocking protocol, frozen tissue sample, oct embedding, optimal cutting temperature, tissue, cryostat, oct
Abstract
This protocol describes the procedure for embedding an already frozen tissue sample into Optimal Cutting Temperature (OCT) compound. The process includes orienting the tissue, embedding it in OCT, curing the compound, and labeling the block. All performed inside a cryostat at −20°C for sectioning.
Materials
- Optimal Cutting Temperature (OCT) embedding compound
- Metal or plastic embedding molds
- Cryostat set to −20°C
- Sharpie marker
Troubleshooting
Before start
Ensure the tissue is fully frozen before beginning the embedding process. The tissue should have been frozen and maintained at −20°C or lower.
Preparation
Ensure the tissue is fully frozen before beginning the embedding process. The tissue should have been frozen and maintained at −20°C or lower.
Embedding Process
Place a small amount of OCT compound into a metal or plastic embedding mold.
Inside the cryostat at −20°C, orient the frozen tissue within the mold so the cutting surface faces upward. Proper orientation is essential for obtaining high-quality sections.
Fill the mold with additional OCT compound to completely encase the tissue, ensuring no air bubbles remain.
Freezing and Curing
Allow the mold with the tissue and OCT to remain inside the cryostat at −20°C until the OCT freezes and cures completely (approximately 30 minutes to 1 hour).
Verify that the OCT block is fully solidified and firm before proceeding.
Labeling
Remove the solidified OCT block from the mold.
Label the block with the specimen ID using a Sharpie marker to ensure proper identification during sectioning.