A microtome is a precision cutting instrument utilized in pathology and histology laboratories for preparing extremely thin sections of biological specimens, typically ranging from 2 to 25 micrometers (μm) in thickness. These sections are mounted on slides and stained for microscopic examination, forming the foundation of histopathological diagnosis. The term "microtome" originates from the Greek words "mikros" (small) and "temnein" (to cut), accurately describing its primary function. The instrument enables the preparation of serial sections—consecutive slices taken through a tissue block—allowing for detailed three-dimensional reconstruction of anatomical structures. Professional terminology associated with microtomy includes paraffin embedding, cryosectioning, specimen orientation, and knife angle adjustment, all critical for optimal section quality.

The fundamental operating principle of a microtome involves the precise mechanical advancement of a tissue block against a stationary cutting blade, or conversely, the movement of a blade across a stationary tissue block. This process requires extremely accurate micron-level adjustments to ensure uniform section thickness. Most modern microtomes employ a feed mechanism based on a precision micrometer screw or stepper motor that advances the specimen in increments corresponding to the desired section thickness. The cutting action can be manual, semi-automatic, or fully automated, with advanced models incorporating precision guidance systems to maintain optimal cutting angles and speeds. For cryostat microtomes used in frozen section techniques, the entire mechanism is housed within a refrigerated chamber maintained at temperatures between -15°C to -30°C to preserve tissue integrity during sectioning.

Microtomes serve several essential functions in pathological practice and research:

Modern microtomes incorporate precision engineering and high-quality materials to ensure consistent performance:

Microtomes find applications across multiple industries and sectors:

Proper installation and operation of microtomes require adherence to strict standards and protocols:

Compliance with International Standards: Microtome installation and operating environments must comply with GMP, ISO 14644 cleanroom standards, and relevant biosafety guidelines. The work area should have appropriate ventilation systems and temperature-humidity controls, maintaining temperature at 20±2°C and relative humidity between 40-60%.

Proper maintenance is essential for ensuring long-term reliable operation of microtomes:

Filter Replacement: For motorized and cryostat microtomes, replace air filters according to manufacturer recommendations, typically every 6-12 months, adjusting frequency based on operating environment.

Record Keeping: Maintain detailed records of all service, calibration, and repair activities, which are essential for quality assurance and compliance audits.

References: ISO 9001:2015 Quality Management Systems, ISO 13485:2016 Medical Devices Quality Management Systems, GMP Good Manufacturing Practice Guidelines, ISO 14644 Cleanrooms and Associated Controlled Environments Standards.