The frozen section technique, also known as cryotomy, is a rapid diagnostic tool used in pathology to analyze tissue samples during surgery. This technique allows surgeons to receive quick information about the tissue which can influence their surgical decisions during the operation.

Compared to traditional biopsy techniques that can take days, frozen sections provide results in 15-30 minutes. This speed is crucial in situations like cancer surgery where knowing if margins are clear can help determine the extent of tissue removal.

Snap Freezing: Tissues are frozen rapidly, typically with liquid nitrogen, at temperatures reaching -20 to -30°C. This rapid freezing minimizes ice crystal formation, which can damage the tissue architecture and hinder accurate diagnosis.

Cryostat: A specialized instrument called a cryostat is used in this technique. It essentially functions as a microtome inside a freezer allowing for the creation of thin tissue sections (as thin as 1 micrometer) at freezing temperatures.

Embedding Medium: Tissue samples are embedded in a cryoprotectant medium, commonly Optimal Cutting Temperature (OCT) compound before freezing. OCT has similar freezing properties to water minimizing tissue distortion during freezing.

Here’s a brief overview of the steps involved in the frozen section technique:

Tissue Acquisition: During surgery, a small piece of tissue is excised from the area of interest.

Embedding: The tissue sample is placed on a metal disc and embedded in OCT medium.

Freezing: The tissue-embedded disc is rapidly frozen using liquid nitrogen.

Sectioning: The frozen tissue block is secured in a chuck within the cryostat and sectioned into thin slices using the microtome blade.

Staining: The sections are transferred to glass slides, stained with dyes and examined under a microscope by a pathologist.

Diagnosis: The pathologist analyzes the microscopic features of the tissue to provide a rapid diagnosis. This technique is performed by Medical Laboratory Technician.