Posted on

What is a Tissue Processor?

What is a Tissue Processor?

A tissue processor is a laboratory instrument used to prepare tissue samples for microscopic examination. It works by dehydrating, clearing, and embedding the tissue samples in a paraffin wax block, which allows for the easy slicing and staining of thin sections for examination under a microscope.

The tissue processing process begins with the selection and preparation of the tissue samples. The samples are typically collected from a biopsy or surgical specimen and are then fixed in a formalin solution to preserve the tissue structure. After fixation, the tissue samples are transferred to the tissue processor and are subjected to a series of chemical and mechanical steps to prepare them for microscopic examination.

The first step in the tissue processing process is dehydration, which removes the water from the tissue samples. This is typically done by placing the tissue samples in a series of increasing concentrations of alcohol, starting with a 50% alcohol solution and ending with a 100% alcohol solution. Dehydration is important because it allows the tissue samples to be embedded in the paraffin wax without becoming distorted or collapsing.

The next step in the tissue processing process is clearing, which removes the alcohol from the tissue samples and replaces it with a clear solvent, such as xylene or toluene. Clearing allows the tissue samples to become transparent, which makes it easier to slice thin sections for microscopic examination.

After clearing, the tissue samples are embedded in a block of paraffin wax. This is done by placing the tissue samples in a mold, covering them with melted paraffin wax, and allowing the wax to solidify. The paraffin wax block provides support for the tissue samples, allowing them to be easily sliced into thin sections for staining and microscopic examination.

Once the tissue samples have been embedded in a paraffin wax block, they can be sliced into thin sections using a microtome. A microtome is a specialized instrument that uses a sharp blade to cut thin slices of the paraffin wax block, typically ranging from 5 to 15 micrometers in thickness. The thin sections are then collected on a glass slide, which can be stained and examined under a microscope.

There are several different types of tissue processors available, each with its own unique features and capabilities. Some tissue processors are automated, meaning that they can run the entire tissue processing process without the need for manual intervention. Other tissue processors are manual, requiring the operator to manually move the tissue samples through each step of the process.

Tissue processors are essential tools in the field of histology, as they allow for the precise and consistent preparation of tissue samples for microscopic examination. They are widely used in hospitals, research laboratories, and pathology labs around the world, and are an integral part of the diagnostic process for many diseases and conditions.

Overall, the tissue processor is a valuable instrument that plays a crucial role in the preparation of tissue samples for microscopic examination. Its ability to dehydrate, clear, and embed tissue samples in a paraffin wax block allows for the easy slicing and staining of thin sections, enabling researchers and clinicians to more accurately diagnose diseases and conditions.

Source articles:

https://www.sigmaaldrich.com/technical-documents/articles/biology/tissue-processing.html

https://www.thermofisher.com/us/en/home/life-science/histology/tissue-processing/tissue-processing-overview.html

https://www.leica-microsystems.com/scientific-resources/white-papers/the-tissue-processing-workflow-from-sampling-to-embedding/