Preparing tissue samples for microscopy requires precision down to the micrometre. A microtome is the essential tool that makes this possible, slicing biological specimens into ultra-thin sections (often just 1-10 micrometres thick) so pathologists and researchers can examine cellular structures under a microscope.

If you’re new to histology or setting up a laboratory, understanding what a microtome is, how it works, and which type suits your needs will save you time, budget, and specimen quality headaches.

Key Insights

• What is a microtome? A precision cutting instrument that slices tissue samples into ultra-thin sections (typically 1-10 µm) for microscopic examination.
• Main microtome uses: Histopathology diagnosis, research tissue analysis, quality control in pharmaceutical manufacturing, and forensic pathology.
• Types of microtomes: Rotary (most common), cryostat (frozen sections), sliding, and ultramicrotomes (electron microscopy).
• Best for beginners: Rotary microtomes offer the best balance of precision, ease of use, and versatility for most histology applications.

What is a Microtome and Why Does Histology Need It?

A microtome is a specialised cutting device designed to produce consistent and precise thin tissue sections with thicknesses measured in micrometres for microscopic study.

Here’s why microtomes are non-negotiable in modern histology: light can only pass through tissue that’s thin enough – usually under 10 micrometres. Without a microtome machine, you simply can’t prepare specimens for diagnostic pathology, cancer research, pharmaceutical testing, or medical education.

Australian pathology laboratories process over 1.2 million histopathology specimens annually, and every single diagnostic slide starts with precision sectioning on a microtome machine.

How Microtomes Work: The Basics

The fundamental principle behind all microtome types is the controlled, repeatable advancement of a specimen block past a sharp blade. Modern microtomes employ a mechanical feed system, typically a precision screw mechanism, that advances the specimen block by a predetermined distance (the section thickness) after each cutting stroke.

The specimen, typically tissue embedded in paraffin wax, is mounted in a metal block holder. As you turn the handwheel (or activate the motor in automated models), the block advances and the blade slices a thin section. These sections are then floated on a water bath, mounted on glass slides, stained, and examined under a microscope.

The magic is in the engineering: high-quality microtomes maintain cutting precision within ±1 micrometre across thousands of sections.

Types of Microtomes: Which One Do You Need?

Rotary Microtomes

Best for: General histopathology, research laboratories, pharmaceutical QC

Rotary microtomes are the workhorse of modern histology labs. They use a rotating wheel mechanism to drive the specimen block past a fixed blade, producing consistent sections from 1-60 micrometres thick.

Why they’re popular: Smooth cutting action, excellent for paraffin-embedded tissues, easy to operate, and suitable for high-volume laboratories. Most Australian pathology labs use rotary microtomes as their primary sectioning tool.

Section thickness range: 0.5-60 µm (typically used at 3-5 µm for diagnostic work)

Cryostat Microtomes

Best for: Frozen section diagnosis, lipid studies, enzyme histochemistry

A cryostat combines a microtome with a freezing chamber (typically -20°C to -30°C), allowing you to section fresh or frozen tissue without paraffin embedding. This is essential for rapid intraoperative diagnosis during surgery.

Critical application: In Australian hospitals, cryostats enable surgeons to get diagnostic results in 15-20 minutes during cancer operations, determining whether they’ve achieved clear surgical margins.

Section thickness range: 3-30 µm

Sliding Microtomes

Best for: Large specimens, botanical samples, hard tissues

Sliding microtomes use a different approach – the specimen block remains stationary while the blade slides across it on a horizontal track. This design excels at cutting larger specimens (like whole brain sections) and harder materials.

When to choose sliding: If you’re sectioning specimens larger than 40mm or working with botanical or bone samples that would challenge a rotary microtome.

Ultramicrotomes

Best for: Electron microscopy, nanotechnology research

Ultramicrotomes create extremely thin sections (50-100 nanometres) for transmission electron microscopy (TEM). These are specialised research instruments, not typically found in routine diagnostic labs.

Section thickness range: 50-100 nm (that’s 0.05-0.1 micrometres, roughly 50 times thinner than routine histology sections)

Common Microtome Uses Across Medical and Research Settings

Diagnostic Histopathology

The primary microtome uses in Australian healthcare involve cancer diagnosis and disease identification. Pathologists examine microtome-cut tissue sections to diagnose melanoma, carcinomas, and hundreds of other conditions.

Pharmaceutical Quality Control

Pharmaceutical manufacturers use microtomes to examine drug formulations, test drug delivery systems, and conduct toxicology studies on animal tissue samples. This is particularly important for meeting Therapeutic Goods Administration (TGA) requirements for new drug applications.

Medical Research

Research applications include studying disease mechanisms, testing new treatments, and examining tissue responses to experimental therapies. Australian medical research institutes rely on high-quality microtomy for a wide range of applications, from immunology studies to neuroscience research.

Forensic Pathology

Forensic pathologists use microtomes to prepare tissue samples during post-mortem examinations, helping determine causes of death and identify disease processes or injuries.

Choosing Your Microtome: What to Consider

• Laboratory volume. High-throughput pathology labs need robust, motorised rotary microtomes. 
• Specimen types. If you’re only working with paraffin-embedded tissues, a quality rotary microtome covers most needs. Need frozen sections? Budget for a cryostat.
• Budget and space. Entry-level rotary microtomes start around $8,000-12,000 AUD, while cryostats begin at $25,000-35,000. 
• Compliance requirements. Government and pharmaceutical laboratories must consider NATA accreditation requirements, TGA compliance, and AS/NZS equipment standards when selecting instruments.
• Support and service. Choose suppliers who offer local technical support, spare parts availability, and service contracts.

Set Your Lab Up for Success

Beyond the microtome itself, you’ll need supporting equipment: a water bath for floating sections, quality slides and coverslips, appropriate staining equipment, and a reliable source of microtome blades.

Budget for training too. While modern microtomes are more user-friendly than ever, proper technique takes practice. Most equipment suppliers offer on-site training, and formal histology courses are available through organisations like the Australian Institute of Medical Scientists (AIMS).

Ready to equip your laboratory with precision microtomy equipment? Explore our range of microtome machines designed for Australian research and diagnostic laboratories, backed by local technical support. Whether you’re setting up a new facility or upgrading existing equipment, our team can help you select the right microtome for your specific applications.