The latest express of tissue block paraffin embedding technology

The latest express of tissue block paraffin embedding technology

The quality of pathological slices directly affects the judgment and treatment of the disease. Every aspect of the slice making process is very important, including good tissue fixation, tissue processing, staining and mounting. Regarding the paraffin embedding technology of tissue blocks, Chinese pathologists have carried out more practice and research, and many papers have been produced.

Common embedding quality problems in daily work

Tissue fixation is unstable and disperses with wax solution (Figure 1); tissue embedding is scattered (Figure 2); tissue faces are not uniform (Figure 3); tissues are placed randomly (Figure 4).

1. The basic standard of embedding

1.1 Selection criteria for the size of the cassette. When embedding, there should be a 1 mm gap between the surrounding tissue block and the bottom edge of the cassette, which means that the tissue block and the cassette are exactly matched. It can match the small embedding cassette for embedding small tissues; it can match the medium-sized embedding cassette for embedding medium-sized tissues.

1.2 Standard for wax injection Fill the entire embedding cassette at one time, but not overflow, to avoid the possibility of tissue washout caused by the second wax filling.

1.3 The standard method of placing the dehydration box is placed horizontally, and the end with the pathological number is to the left. Place it in the center, without shifting to the left or right.

1.4 Organizational positioning standards The embedding organization is centered.

1.5 Standards for tissue gathering: Tightly gather, without obvious gaps visible to the naked eye.

1.6 The embedding level standard of the tissue The embedding surface is the same height to ensure that the repairing can be in place at one time, the thickness of the wax block is the same, and there is no unevenness between the tissue blocks.

1.7 The standard of organization arrangement is neat and square arrangement is preferred; if squares cannot be arranged, the arrangement is rectangular, and it should be in vertical rows.

1.8 The organization blocks are arranged in the same direction.

1.9 Standards for embedding surface: Those with cutting surface requirements face down with the largest cutting surface, those without cutting surface requirements face down, and the skin surface, intestinal wall inner membrane surface, and cyst wall inner membrane surface face to the left. The lumen, cyst wall, skin, etc. should be buried vertically, so that the tissue structure of each layer can be seen under the microscope after the section is stained. For example, the skin must have epidermis and dermis or subcutaneous tissue, the intestinal and stomach walls must have mucosa, submucosa, muscle and serosal layers, and the kidneys must have cortex and medulla.

When embedding the cyst tissue blocks, they are gathered together, side by side, and embedded in the center (Figure 5); when the skin tissue blocks are embedded, the skin faces the pathological direction of the wax block (Figure 6); when the endometrial and muscle tissue blocks are embedded longitudinally Columns, side by side, and centered (Figure 7); cervical tissue blocks are embedded in rows, side by side, and centered (Figure 8).

1.10 The wax block has no bubbles.

1.11 Pollution-free embedding There is no pollution from other tissues, wireless heads, staples, and paper.

1.12 The tissue and the wax block are all fused The wax immersed and adhered inside and outside the tissue is fully melted during embedding, and no solidification should occur. The embedding speed should be fast to avoid solidification of the melting wax before the tissue block is fully embedded.

1.13 Temperature standard for embedding paraffin wax The temperature difference between the embedding paraffin wax and the tissue immersion agent is 2 ℃, both of which have a melting state, so that the tissue and the embedding paraffin can be the same after embedding the condensed wax block. Otherwise, if the temperature of embedding paraffin wax is too low, the paraffin wax will start to condense during embedding, and it is too late to operate, and it is easy to bring in air bubbles, so that after the embedding wax block is condensed, the density of the wax block often appears uneven, and the tissue is separated from the paraffin wax, making it difficult to cut out Complete sections, if these conditions occur, re-immersion in wax embedding.

2. Preparation work standard before embedding

2.1 Standards for checking the status of the instrument Check the power-on status, and the wax nozzles are draining wax normally.

2.2 Preparation standards for embedding tools: 3 clean tweezers, 6 trays, and 1 garbage tray.

2.3 Preparation standards for embedding anti-pollution: A stack of paper towels and a pack of cotton swabs.

2.4 The preparation of the embedding molds The standard embedding frames are arranged neatly, and the large, medium, and small sizes are disassembled and laid out flat to avoid looking for embedding molds during the embedding process to facilitate selection and taking, and avoid embedding The frame is connected due to the cooling of the wax liquid, and it is not easy to separate and take.

2.5 Prepare a technical worksheet. Check the total number of wax blocks before embedding to prevent loss of wax blocks; check the number of tissue blocks during embedding to prevent loss of tissue blocks; instruct employees to embed the tissue in a suitable way to prevent embedding surface errors.

2.6 The temporary storage box of the tissue block is filled with wax liquid. The amount of liquid is about 2 /3 of the height of the dehydration box to ensure that the tissue is always in a state of wax soaking and avoid cavitation and infusion of the tissue with the wax liquid.

3. The operating standards and significance of embedding

3.1 One-time wax injection Standard: The wax liquid is filled up at one time, but does not overflow.

3.2 Avoid tissue block confusion Criteria:

①Only one wax block to be wrapped will always appear on the embedding table;

②The opening action should be light;

③When opening the box, pay attention to whether there is tissue popping out.

3.3 Organizational placement standards:

①According to the technical worksheet, identify the type of organization;

②Do a good job of organizational placement planning and fixed-point positioning on the hot stage;

③Move the organization to the cold stage for cooling.

Significance: To reduce the unevenness of the tissue caused by the slow embedding speed, which may result in the fragmentation of the tissue, excessive trimming and destruction of the tissue, and the appearance of cracks between the tissues.

3.4 The embedding surface cooling standard:

①Put about 2/3 of the water on the small cold table;

②If the water is difficult to retain, wax around the small cold table.

Significance:

① Speed up the cooling rate;

② Ensure uniform cooling surface;

③ Solve the deterioration of cooling quality caused by poor cooling function of the small cold table;

④ Reduce the time waste of scraping wax liquid lumps due to the wax sticking on the small cold table .

3.5 Once in place Standard: Press the embedding mold at one time.

Jiangsu Huida is a manufacturing enterprise specialized in providing embedding cassette. The company sets research and development, production, sales and after-sales service as one, to provide customers with embedding cassette. After years of development, the company has been adhering to the “customer first, excellence” business philosophy, adhere to the “customer first” principle to provide our customers with quality services