tissue processing

Tissue processing is a crucial step in many biological and medical research fields as well as in clinical diagnostics. It involves a series of procedures that prepare tissue samples for further analysis, such as histological examination, immunohistochemistry, or molecular analysis.

1. Fixation
  - Fixation is the first and one of the most important steps. It aims to preserve the tissue in as close to its in - vivo state as possible. The most common fixative is formaldehyde. When tissue is immersed in a formaldehyde - based fixative, it cross - links proteins, preventing degradation and autolysis. This step stabilizes the tissue structure, including cells, organelles, and extracellular matrix. For example, in a biopsy sample, proper fixation ensures that the abnormal cells, which may be the focus of a cancer diagnosis, are preserved intact for accurate examination.
2. Dehydration
  - After fixation, the tissue needs to be dehydrated. Water in the tissue is gradually replaced with alcohols, usually ethanol. This is necessary because most embedding media, such as paraffin, are not miscible with water. The process of dehydration must be carefully controlled to avoid excessive shrinkage or distortion of the tissue. A step - wise increase in the concentration of ethanol, starting from lower concentrations like 70% and gradually increasing to 100%, is typically employed.

Once the tissue is dehydrated, the next step is clearing. The purpose of clearing is to remove the alcohol and replace it with a substance that is miscible with the embedding medium. Xylene is a commonly used clearing agent. Clearing makes the tissue more transparent, which is important for proper embedding. It also helps to further remove any remaining water - alcohol mixtures from the tissue. However, xylene is a toxic substance, and proper safety precautions, such as working in a fume hood, are essential during this step.

1. Paraffin Embedding
  - Paraffin is the most widely used embedding medium for tissue processing. The cleared tissue is placed in molten paraffin, which then solidifies around the tissue when cooled. This creates a hard block that can be easily sectioned. Paraffin - embedded tissues are suitable for thin - sectioning, which is necessary for histological staining and microscopic examination.
2. Alternatives to Paraffin
  - In some cases, other embedding media may be used. For example, for certain types of electron microscopy, resins such as epoxy resins are preferred. Resin - embedded tissues can provide better preservation of ultrastructural details compared to paraffin - embedded tissues.

After embedding, the tissue block is sectioned using a microtome. The sections, which are typically only a few micrometers thick, are then mounted onto glass slides. Mounting is important as it provides a stable platform for further staining and analysis.

Tissue processing is a complex but essential set of procedures. Each step, from fixation to mounting, plays a vital role in ensuring that the tissue sample is in the best condition for accurate analysis. With continuous advancements in technology and research, new methods and reagents for tissue processing are being developed to improve the quality of tissue samples and the accuracy of subsequent analyses.

Performance Features:
1. High sensitivity color touch screen, Chinese display interface, capable of file editing, suitable for customer use;
2. Automatic wax recovery function, saving reagents, and cleaning thoroughly;
3. Independent pipeline design for reagent paraffin, reducing operational risks;
4. One-click cleaning function, retrievable at any time, automatic cleaning;
5. Non-contact thermal pressure detection technology, monitoring reagent operation status, and automatically correcting operation procedures based on monitoring data.
6. Positive and negative dual pressure control technology, reducing operational risks;
7. Self-locking cylinder cover design, anti-static mechanical handle switch, making specimen placement and retrieval effortless;
8. Set usage count threshold, pop-up prompt for reagent replacement when exceeding threshold;
9. The circulation system is equipped with an activated carbon filter to reduce environmental pollution;
10. Equipped with password protection and power-off memory protection functions;
11. Constant temperature control during the dehydration process;
12. Timed startup to meet holiday needs
13. Dimensions: 670*565*1270MM;

Technical Parameters:
1. Specimen processing capacity: 180 standard embedding boxes;
2. Sample baskets: 3;
3. Reagent containers: 9 reagent tanks (2.5L each); 3 paraffin tanks (2.5L each);
4. Cleaning containers: 3;
5. Condensation bottle: 1 (external);

Operation:
1. Operation programs: store 20;
2. Cleaning cycle programs: 4;
3. Paraffin temperature range: room temperature ~ 85°C;
4. Temperature accuracy: ±1°C;
5. Vacuum degree: -0.06MPa;
6. Power supply: 220V, 50Hz P<1200W;