Optimal cutting temperature compound

Optimal Cutting Temperature (OCT) Compound is a water-soluble substance used in the preparation of tissue samples for cryosectioning in histology and pathology. OCT compound provides a medium that supports the tissue sample, allowing it to be cut at very low temperatures without fracturing, thereby preserving the structural integrity of the sample for microscopic examination.

Composition

OCT compound typically consists of a mixture of polyvinyl alcohol, polyethylene glycol, and non-reactive resins. This combination gives the compound its characteristic viscosity and low-temperature performance, enabling it to infiltrate the tissue without causing damage or significant alteration.

Application

The primary use of OCT compound is in the preparation of tissue samples for cryostat sectioning. The process involves embedding the tissue within the OCT compound, which then rapidly solidifies when cooled to the optimal cutting temperature, usually around -20°C to -30°C. This solid matrix supports the tissue, allowing for the creation of thin, uniform sections using a cryostat, a specialized type of microtome designed for cutting at low temperatures.

Advantages

The use of OCT compound in cryosectioning offers several advantages:

• It preserves the tissue's hydration state, which is crucial for maintaining enzyme activity and antigenicity for subsequent immunohistochemistry (IHC) or in situ hybridization (ISH) analyses.
• It provides excellent structural support, enabling the cutting of very thin sections without distortion or damage to the tissue architecture.
• It is easily removed from the final preparation, as it is soluble in water and many aqueous solutions, facilitating further staining or analysis without interference.

Considerations

While OCT compound is widely used and highly effective, there are some considerations to keep in mind:

• The choice of OCT compound and the specifics of its application can affect the quality of the tissue sections and the results of subsequent analyses. It is important to follow established protocols and adjust techniques as necessary for specific tissue types or research objectives.
• OCT compound is designed for use at low temperatures and may not perform well if not properly cooled or if used outside its optimal temperature range.

Conclusion

OCT compound is an essential tool in the field of histology and pathology, enabling the preparation of high-quality tissue sections for microscopic examination and analysis. Its ease of use, combined with the quality of results it enables, makes it a staple in laboratories focusing on tissue analysis.