Description
Basic trans-illumination where contrast arises from light absorption by the specimen; typically used for fixed, stained tissues.
How this lab uses this technology
Microtome sectioning is used to obtain thin sections of biological samples for examination by light microscopy. Depending on the specimen and the experimental objective, tissues may be embedded in paraffin, resin or another suitable support medium before sectioning.
The embedded sample is mounted in the microtome and cut using a precision blade. The resulting sections are collected on glass slides and may subsequently be stained, labelled or processed for histological, immunohistochemical, fluorescence or morphometric analysis.
Applications
Microtome sectioning is suitable for (among others):
Histological examination of plant and animal tissues
Analysis of tissue organization and cellular morphology
Paraffin-embedded tissue sectioning
Resin-embedded semithin sectioning
Immunohistochemistry and immunofluorescence
In situ hybridization
Morphometric and quantitative image analysis
Identification of regions of interest for subsequent electron microscopy
Evaluation of structural alterations caused by treatments or experimental conditions
Sample Preparation
The sample-preparation protocol depends on the type of tissue, the embedding medium and the downstream application. Samples are generally fixed, dehydrated and embedded before sectioning.
Section thickness is selected according to the imaging method and scientific objective.
Paraffin sections are commonly prepared at a thickness of a few micrometres, while resin-embedded semithin sections are usually thinner and provide improved structural resolution.
Advantages
Microtome sectioning provides:
Reproducible thin sections
Good preservation of tissue architecture
Compatibility with a wide range of staining and labelling methods
Preparation of serial sections
Reliable comparison between samples and experimental groups
Suitable sections for qualitative and quantitative image analysis
Factors Affecting Section Quality
The quality of the sections depends on:
Proper fixation and embedding
Sample orientation
Block hardness
Blade condition and cutting angle
Cutting speed
Section thickness
Tissue consistency and heterogeneity
Lab-specific experience
CTEM provides support for the preparation and sectioning of plant and animal tissues for light-microscopy applications.
Users are encouraged to contact the CTEM technical staff before sample collection or fixation to determine the most appropriate embedding medium, section thickness, staining method and imaging strategy for their study.