Manual Microtome Series

• Specifications
• Introduction
• Apparatus
• Protocol
• Applications
• Precautions
• References

Specifications

Features

Standard Manual Microtome RF-RD-315

Profesional Manual Microtome RF-RD-475

Advanced Manual Microtome RF-RD-495

This model is a cost-effective and reliable workhorse for pathology labs, a staple for nearly two decades.

• Economical Value: Offers a strong balance of price, quality, and easy maintenance. It's an ideal starting point for pathologists new to  products.

• Robust & Clean Design: Features an easy-to-clean housing and a sturdy base for stable operation. Includes a wide, removable waste tray for simple cleanup.

• Manual Handwheel with Safety Locks: The light-turning handwheel has an ergonomic handle to reduce fatigue. It includes two independent locking devices:

  • One lock (via the handle) secures the specimen head in the safest, uppermost position for blade or sample changes.

  • A second lever lock allows you to secure the handwheel at any position.

• Accessible Coarse Feed: The coarse feed wheel is positioned low on the left side for comfortable, fatigue-free trimming.

• High Precision & Stable Movement: Engineered for accurate and consistent sectioning.

• Robust & Clean Design: Like the RD-315, it features an easy-to-clean housing and a stable base. It also comes with a wide, removable waste tray for convenient cleaning.

• Enhanced Manual Handwheel: Features two independent locking systems: one to lock the handwheel at any 360-degree position, and another for quick locking at the top end.

• Optimized Sample Movement: Offers fine-tuned control for sample advancement and retraction, including continuous movement from 0.1mm/s to 3.5mm/s, and single-point steps from 1µm to 60µm.

• Personalized Small Handwheel: This "rough repair wheel" automatically disengages front and rear limits, preventing equipment damage if the sample moves beyond its set boundaries.

• Superior Sectioning Precision: Utilizes imported cross-roller guide rails and a screw motion mechanism for extremely precise and stable sectioning.

• Adjustable Specimen Angle: The cassette holder can be locked at any point along three axes, allowing for easy and precise adjustment of the sectioning angle.

• Versatile Clamping: Allows for quick and easy switching between different specimen clamps, offering options for both paraffin blocks and cassettes.

• Multiple Functions: Includes specimen retraction and trimming functions, along with a replaceable specimen holding system for flexibility.

• Accurate Positioning: Features a precise positioning system that is user-friendly and provides accurate adjustments along both X- and Y-axes.

Introduction

Manual rotary microtomes are essential tools in various scientific and medical fields, particularly in histology, pathology, and material science, where the preparation of thin, uniform tissue sections is critical for microscopic examination. Our manual microtomes offer reliable performance, ease of use, and robust construction, making them indispensable for both routine laboratory work and more specialized research applications. This series is designed to provide consistent, high-quality sections, enabling accurate diagnosis, detailed research, and effective material analysis.

Parts of Rotary Microtome

• Knife Holder Base

The knife holder base holds the holder in place on the microtome stage. It can be moved to or away from the block, but it must remain fixed and secured during microtomy.

• Knife Holder

The knife holder comprises various parts, including the blade clamp, which holds the blade, the knife tilt, which adjusts the knife angle, and the faceplate, which directs the ribbons away from the blade and toward the operator.

• Microtome Body 

The microtome body is a platform with rails that keeps the knife holder base in place.

• Cassette clamp or block holder

The block holder or cassette clamp holds the paraffin block in place. The block usually slides up and down with each revolution while the blade remains stationary. The block holder may be equipped with knobs that enable the operator to move the block face in different directions to line the tissue with the blade.

• Advancement Handwheel

The advancement handwheel rotates in one direction, moving the block closer to the knife at the preset microns.

• Coarse Handwheel

The coarse handwheel moves the block closer or away from the knife.

• Micron Adjustment

Micron adjustment is used to adjust settings for slice thickness that vary from 1 to 60 microns.

• Safety Lock

The handwheel includes a safety lock that prevents the wheel from loosening and the block holder from falling towards the blade when inserting or removing a block. 

Principle

The fundamental principle of all rotary microtomes, including our manual models, involves a precise mechanical action to achieve uniform tissue sections. A fixed tissue block, embedded in paraffin or resin, is mounted onto a specimen clamp. As the manual handwheel is rotated, a precisely engineered feeding mechanism advances the specimen block towards a stationary cutting blade. During each rotation, the specimen block moves past the blade, and a thin section of tissue is cleanly sliced off. The thickness of this section is determined by a highly accurate micrometer-based feed mechanism, which can be adjusted to increments as small as 1 micrometer. This continuous, controlled movement ensures that each section is of consistent thickness, critical for reproducible results in microscopy. Features like specimen retraction in models like the RD-315, RD-475, and RD-495 prevent the specimen from rubbing against the blade on the return stroke, extending blade life and improving section quality

Protocol

1. Embed the sample in a paraffin cartridge.
2. Mount it on the paraffin block/sample holder.
3. Set the distance between your knife blade and paraffin block using the coarse handwheel.
4. Carefully install the blade and fix it in the knife holder.
5. Set the required microns size by using the micron adjustment knob.
6. Unlock the handle-equipped wheel by pushing the pin button-down located on its top.
7. Revolve the handle-equipped wheel to operate the rotary microtome.
8. Continue to cut until you get your desired sample.

Strengths and Limitations

The Rotary microtome is used to cut biological specimens according to the desired thickness ranging from 1 to 60 microns. It may be adapted to various types of tissue sectioning (hard, brittle, or fatty). However, it is not suitable for large tissue sectioning. Technological advancements in the rotary microtome have enhanced section quality, boosted production, and improved the technologist's occupational safety. 

The incidence of repetitive motion disorders, a frequent occupational health concern in the histology laboratory, may be reduced by eliminating the manual hand-wheel operation of the microtome. Disposable blades are used, eliminating the need for sharpening and increasing sample size accuracy. Additionally, knives can be used in place of blades; they are thick and large and produce fewer vibrations during microtomy. A high-resolution motor makes a stable and smooth automatic slicing system. Its heavier size makes it stable, and it is crucial to avoid undulations in the paraffin sections. A double locking system makes it secure and prevents injuries during block handling. An emergency button is used to stop the operation in danger. It is anti-static, non-waxing, and is very easy to clean. It has four different automatic slicing modes that cover a lot of sampling situations. Daily cleaning from paraffin residue maintains a microtome cutting ideally for many years.

The heavy size of the rotary microtome makes it less portable. The disposable blades are expensive and need to be handled with care to avoid accidents. Moreover, the knives get dull if they aren't used on decalcified tissue that hasn't been cleaned. 

Summary

1. The Rotary microtome uses a rotary motion to cut the sections of samples used in microscopy. It is used to prepare thin layers of bone, mineral, teeth, and hair with section thicknesses ranging from 1-micron to 60 microns.
2. It  uses a staged rotary action where the specimen is cut with the circular motion of the handwheel. The cutting procedure is done with a knife or disposable blade placed within the instrument.
3. It has various parts: knife holder base, knife holder, microtome body, cassette clamp or block holder, advancement handwheel, coarse handwheel, micron adjustment knob, and safety lock.
4. It has thick and large knives that produce fewer vibrations. A high-resolution motor is used that creates a high-precision, stable, and smooth automatic slicing system.
5. The rotary microtome is used in various microbiological labs, including histopathology/anatomical pathology labs.
6. The blades of the rotary microtome should be handled with care. Always use cut-resistant gloves to remove the blades. Before cleaning, remove the blades from the holder and lock the rotary machine.

References

1. Tosney, K. W., & Landmesser, L. T. (1986). Neurites and growth cones in the chick embryo. Enhanced tissue preservation and visualization of HRP-labeled subpopulations in serial 25-microns plastic sections cut on a rotary microtome. Journal of Histochemistry & Cytochemistry, 34(7), 953–957. https://doi.org/10.1177/34.7.3519758 

1. Sharma, R. (2022). Microtomy. Retrieved February 5, 2022, from Slideshare.net website: https://www.slideshare.net/candysharma777/microtomy-67236029
2. Frimiano, E M S, N, C. N., A, V. D., Sales, A., Mendes, & A, N. A. (2022). Histological study of the liver of the lizard Tropidurus torquatusWied 1820, (Squamata: Tropiduridae)(AU). Braz. J. Morphol. Sci, 165–170. Retrieved from https://pesquisa.bvsalud.org/portal/resource/pt/lil-644137
3. Muhd-Farouk, H., Amin-Safwan, A., Mahsol, H., & Ikhwanuddin, M. (2017). Histological Characteristics on the Testes of Mud Spiny Lobster, Panulirus polyphagus (Herbst, 1793). Pakistan Journal of Biological Sciences: PJBS, 20(7), 365-371. https://doi.org/10.3923/pjbs.2017.365.371
4. Sy, J., & Ang, L.-C. (2018). Microtomy: Cutting Formalin-Fixed, Paraffin-Embedded Sections. Methods in Molecular Biology, 269–278. https://doi.org/10.1007/978-1-4939-8935-5_23