What is Proper Handling in Histology?
Proper handling in histology involves meticulous techniques to ensure the integrity of tissue samples from collection to microscopic examination. This encompasses specimen collection, fixation, processing, embedding, sectioning, staining, and storage.
How Should Specimen Collection Be Conducted?
Specimen collection should be performed using sterile instruments to prevent contamination. The tissues should be handled gently to avoid crushing. Immediate fixation in an appropriate fixative, such as
formalin, is essential to preserve cellular structures.
What Are the Best Practices for Fixation?
Fixation is a critical step that stabilizes and preserves tissue morphology. The tissue should be immersed in a volume of fixative that is at least 10 times the volume of the specimen. The choice of fixative depends on the type of tissue and the specific histological technique intended. Formalin is widely used, but other fixatives like
glutaraldehyde might be preferred for electron microscopy.
What is Involved in Tissue Processing?
Tissue processing involves dehydration, clearing, and infiltration with a medium like paraffin. Dehydration is typically done using graded alcohols, followed by clearing agents such as xylene to remove alcohol. Finally, the tissues are infiltrated with molten paraffin wax.
How is Embedding Done?
Embedding involves placing the tissue into a block of paraffin wax, which provides support for thin sectioning. The tissue must be oriented correctly within the paraffin to ensure that the sections cut will provide the best view of the tissue’s architecture.
What Are the Key Steps in Sectioning?
Sectioning involves cutting thin slices of the embedded tissue using a microtome. Sections are usually 3-5 micrometers thick. The quality of sections depends on the sharpness of the blade and the technique of the histotechnologist. Sections are floated on a warm water bath to remove wrinkles and then picked up on glass slides.
How Should Slides Be Stored?
Slides should be stored in a dry, dust-free environment to prevent deterioration. Proper labeling with patient information and date is essential for tracking and future reference.
How Can One Avoid Common Artifacts?
Artifacts can arise from improper handling at any stage. To avoid them, ensure rapid fixation, avoid over-dehydration or under-clearing during processing, and handle tissues gently. Regular maintenance of equipment like microtomes and staining machines is also crucial.
Conclusion
Proper handling in histology is a multi-step process that requires attention to detail at every stage. From collection to storage, each step must be performed meticulously to ensure the highest quality of tissue samples for accurate diagnosis. Understanding and adhering to best practices in handling are essential for the reliability and reproducibility of histological analyses.
