Dehydration embedding method for manufacturing rat spinal cord tissue paraffin block

Abstract

The invention relates to the technical field of biological research, and discloses a dehydration embedding method for manufacturing a rat spinal cord tissue paraffin block. The rat spinal cord tissue is subjected to gradient dehydration by adopting a gradient ethanol dehydration treatment mode, and the condition of incomplete dehydration of the rat spinal cord tissue is not easy to occur, so that the condition that subsequent paraffin cannot completely permeate to influence slices is avoided to a great extent, and the effect of stable and efficient dehydration treatment on the rat spinal cord is achieved by adopting the method; according to the method, the stability of subsequent waxing and embedding is also promoted, echelon waxing treatment is also adopted in the waxing treatment, and a freezing table is adopted in the embedding treatment to carry out second-reading control cooling, so that the condition that tissues become hard due to too high paraffin temperature or too long paraffin time is avoided; and the crystallization phenomenon caused by inaccurate cooling control and excessive cooling is avoided, so that the influence on the slice is avoided by strictly controlling the gradient wax dipping and cooling speed, and the wax dipping embedding treatment efficiency and stability are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of biological research, and in particular to a dehydration embedding method for preparing a paraffin block of rat spinal cord tissue. Background Art

[0002] In the process of preparing biological specimens for pathological sections, paraffin blocks are basically used to fix the biological specimens for pathological sections. The fixation and preparation of paraffin blocks for the biological specimens is an important link. In this link, embedding unsuitable tissues is very likely to cause problems such as fragile tissue section staining, easy detachment, and inaccurate staining results. Because different tissues have different sizes and textures, the requirements for each step in the paraffin block preparation process are also different.

[0003] In basic biological research, the most commonly used experimental animal for spinal cord research is the rat (a type of white mouse, similar to a mouse but larger in size, more ferocious in temperament, stronger in disease resistance, longer incisors, strong adaptability to the external environment, adult rats rarely get sick, generally not very invasive, can be raised in large numbers, and will not bite people); However, due to the small size and special texture of rat spinal cord tissue, and the significant differences between rat brain and other tissues, the steps and time of dehydration and embedding are very difficult to control during the paraffin block preparation process. Problems such as incomplete dehydration, improper wax immersion and embedding are prone to occur. The lack of an efficient and stable dehydration and embedding method for the preparation of rat spinal cord tissue paraffin blocks is not conducive to biological and pathological research. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue, which solves the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A dehydration embedding method for preparing a paraffin block of rat spinal cord tissue comprises the following steps: S1: tissue sampling and fixation; S2: Rinse the sampled tissue; S3: Dehydration of the sampled tissues with gradient ethanol; S4: The sampled tissue is treated with xylene to replace ethanol; S5: Wax treatment of the sampled tissue; S6: embedding the sampled tissue; The step S3 comprises the following specific steps: S301: the washed rat spinal cord group was placed in a 65% ethanol solution and soaked for 30 minutes; S302: After being taken out in the previous step, the sample is again placed in a 75% ethanol solution and soaked for 30 minutes; S303: After being taken out in the previous step, the sample is again placed in an 85% ethanol solution and soaked for 30 minutes; S304: After being taken out in the previous step, the sample is again placed in 95% ethanol solution I and soaked for 30 minutes; S305: After being taken out in the previous step, it is again placed in 95% ethanol solution II and soaked for 12 hours; S306: After being taken out in the previous step, the sample is again immersed in 100% ethanol I for 30 minutes; S307: After being taken out in the previous step, the sample is again placed in 100% ethanol II and soaked for 60 minutes; The step S4 comprises the following specific steps: S401: placing the rat spinal cord tissue that has been gradient dehydrated in step S3 into xylene I and soaking it for 10 minutes; S402: Take it out again and soak it in xylene II for 25 minutes; The step S5 comprises the following specific steps: S501: placing the rat spinal cord tissue that has been replaced with xylene in step S4 into wax solution I and soaking it for 1 hour; S502: taking out the rat spinal cord tissue soaked in step S501 and soaking it in wax liquid II for 1 hour; S503: taking out the rat spinal cord tissue soaked in step S502 and soaking it in wax solution III for 1 hour; The step S6 comprises the following specific steps: S601: placing the rat spinal cord tissue dipped in wax in step S502 into a tissue embedding mold for 30 minutes, placing the mold on a freezing table for 3 seconds to solidify the wax liquid on the mold surface, and fixing the direction and position of the rat spinal cord tissue in the mold; S602: Fill the mold set in step S601 with wax liquid, place it on a freezing table and wait for the wax to completely solidify, then gently remove the wax block from the mold, and then embed the wax block for long-term storage at room temperature.

[0006] Preferably, the step S1 comprises: S101: First, the rat was anesthetized to death and placed in a supine position on a dissecting table. The rat's chest was cut open to expose the heart. A syringe needle was inserted into the left ventricle from the apex of the heart and the right atrial appendage was cut open. Normal saline was perfused with a syringe until the rat's liver changed color. Then, 4% paraformaldehyde universal tissue fixative was continuously perfused until the rat became hard. S102: Cut the rat spinal cord and the vertebral column after the treatment in step S102, soak them in a conventional 4% paraformaldehyde universal tissue fixative I for 24 hours, and then soak them in a new 4% paraformaldehyde universal tissue fixative II for 24 hours; S103: Cut open the vertebral canal of the rat spinal cord and the spinal column tissue after the immersion treatment in step S102, remove the rat spinal cord from the spinal column, and fix the rat spinal cord in 4% paraformaldehyde universal tissue fixative for 24 hours, wherein the volume ratio of the rat spinal cord tissue volume to the 4% paraformaldehyde universal tissue fixative is 1:50.

[0007] Preferably, the step S2 comprises: S201: trimming the rat spinal cord tissue after the fixation treatment in step S103, removing the unnecessary tissue, and placing the trimmed rat spinal cord tissue into an embedding box for marking; S202: The rat spinal cord tissue that has been trimmed and marked in step S201 is washed with running water, avoiding direct water flow, and is rinsed and soaked with a small water flow for 12 hours to rinse away the paraformaldehyde in the rat spinal cord tissue.

[0008] Preferably, before the rat is anesthetized to death in step S101, a pretreatment operation needs to be performed, which specifically includes the following steps: S1001: Ensure that appropriate tools are available: hemostats, tweezers, scissors, and appropriate protective equipment: gloves and goggles; S1002: Use appropriate anesthesia methods to ensure that rats do not feel pain or stress during the sampling process, and avoid stress reactions in rats that may affect the quality of the sampling; S1003: Disinfect the rat's body surface and the sampling environment to reduce the risk of infection.

[0009] Preferably, the 95% ethanol solution I for soaking in step S304 and the 95% ethanol solution II for soaking in step S305 are configured separately, that is, the ethanol solution I and the ethanol solution II are non-reusable ethanol solutions.

[0010] Preferably, the ethanol I soaked in step S306 and the ethanol II soaked in step S307 are configured separately, that is, the ethanol I and ethanol II are non-reusable ethanol.

[0011] Preferably, the volume ratio of the tissue volume of the rat spinal cord and spine treated in step S102 to 4% paraformaldehyde universal tissue fixative is 1:50, and the conventional 4% paraformaldehyde universal tissue fixative I and fixative II configured in step S102 and the conventional 4% paraformaldehyde universal tissue fixative configured in step S103 are configured separately and cannot be reused.

[0012] Preferably, the xylene I configured in step S401 and the xylene II configured in step S402 are xylenes configured separately, and the xylene I and xylene II are not reusable.

[0013] Preferably, the wax liquid I configured in step S501, the wax liquid II configured in step S502, and the wax liquid III configured in step S503 are all separately configured pure wax liquids, and the wax liquids I, II, and III are not reusable.

[0014] Preferably, when the wax liquid III and the tissue soaked therein are embedded in the mold in step S601, the wax liquid needs to be placed together, and the surface of the mold needs to be covered with the wax liquid, and the rat spinal cord tissue is placed according to the required section.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The invention discloses a dehydration and embedding method for preparing paraffin blocks of rat spinal cord tissue. The method comprises the following steps: performing gradient dehydration on the rat spinal cord tissue by using gradient ethanol dehydration treatment, performing gradient dehydration treatment by using ethanol solution and ethanol with gradually increasing concentrations, and setting ethanol solution I and ethanol solution II with concentrations of 95% and ethanol I and ethanol II with concentrations of 100% for repeated immersion. After the dehydration treatment of the rat spinal cord tissue, the rat spinal cord tissue is not easily dehydrated completely, thereby avoiding the situation that the subsequent paraffin cannot be completely penetrated and affects the sectioning to a great extent. The method achieves the effect of stable and efficient dehydration treatment of the rat spinal cord, promotes the stability of subsequent wax immersion and embedding, and greatly improves the success rate of preparing paraffin blocks of rat spinal cord tissue.

[0016] 2. The dehydration and embedding method for preparing rat spinal cord tissue paraffin blocks adopts a stepwise immersion in xylene treatment process, so that the rat spinal cord tissue can more efficiently replace ethanol after being immersed in ethanol for dehydration treatment, thereby promoting the stability of subsequent wax immersion treatment and embedding treatment, and promoting the full penetration of paraffin. In the wax immersion treatment, a stepwise wax immersion treatment is also adopted, and in the embedding treatment, a freezing table is used for countdown control and cooling, thereby avoiding the situation that the paraffin temperature is too high or the time is too long, causing the tissue to harden, and also avoiding the crystallization phenomenon caused by inaccurate cooling control and excessive cooling. Therefore, by strictly controlling the stepwise wax immersion and cooling speed, the situation that the tissue hardens and crystallizes due to improper wax immersion and embedding treatment is avoided, and the influence on the slice is avoided, and the efficiency and stability of the wax immersion embedding treatment are greatly improved.

[0017] In summary, the present invention provides a dehydration embedding method for preparing wax blocks of rat spinal cord tissue, which solves the problem of fragile and easy to crack tissue during the preparation of wax blocks of rat spinal cord tissue in biomedical research due to its tissue particularity, and greatly promotes the efficiency of biological research and pathological research. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the process of the present invention; Figure 2 This is a specific flow chart of step S1 of the present invention; Figure 3 This is a specific flow chart of step S2 of the present invention; Figure 4 This is a specific flow chart of step S3 of the present invention; Figure 5 This is a specific flow chart of step S4 of the present invention; Figure 6 This is a specific flow chart of step S5 of the present invention; Figure 7 This is a specific flow chart of step S6 of the present invention; Figure 8 This is a schematic diagram of a specific flow chart of step S101 of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example: Refer to Figure 1-8 A dehydration embedding method for preparing a paraffin block of rat spinal cord tissue comprises the following steps: S1: tissue sampling and fixation; S2: Rinse the sampled tissue; S3: Dehydration of the sampled tissues with gradient ethanol; S4: The sampled tissue is treated with xylene to replace ethanol; S5: Wax treatment of the sampled tissue; S6: embedding the sampled tissue; Step S3 includes the following specific steps: S301: the washed rat spinal cord group was placed in a 65% ethanol solution and soaked for 30 minutes; S302: After being taken out in the previous step, the sample is again placed in a 75% ethanol solution and soaked for 30 minutes; S303: After being taken out in the previous step, the sample is again placed in an 85% ethanol solution and soaked for 30 minutes; S304: After being taken out in the previous step, the sample is again placed in 95% ethanol solution I and soaked for 30 minutes; S305: After being taken out in the previous step, it is again placed in 95% ethanol solution II and soaked for 12 hours; S306: After being taken out in the previous step, the sample is again immersed in 100% ethanol I for 30 minutes; S307: After being taken out in the previous step, the sample is again placed in 100% ethanol II and soaked for 60 minutes; Step S4 includes the following specific steps: S401: placing the rat spinal cord tissue that has been gradient dehydrated in step S3 into xylene I and soaking it for 10 minutes; S402: Take it out again and soak it in xylene II for 25 minutes; Step S5 includes the following specific steps: S501: placing the rat spinal cord tissue that has been replaced with xylene in step S4 into wax solution I and soaking it for 1 hour; S502: taking out the rat spinal cord tissue soaked in step S501 and soaking it in wax liquid II for 1 hour; S503: taking out the rat spinal cord tissue soaked in step S502 and soaking it in wax solution III for 1 hour; Step S6 includes the following specific steps: S601: placing the rat spinal cord tissue dipped in wax in step S502 into a tissue embedding mold for 30 minutes, placing the mold on a freezing table for 3 seconds to solidify the wax liquid on the mold surface, and fixing the direction and position of the rat spinal cord tissue in the mold; S602: Fill the mold set in step S601 with wax liquid, place it on a freezing table and wait for the wax to completely solidify, then gently remove the wax block from the mold, and then embed the wax block for long-term storage at room temperature.

[0021] In the present invention, step S1 includes: S101: First, the rat was anesthetized to death and placed in a supine position on a dissecting table. The rat's chest was cut open to expose the heart. A syringe needle was inserted into the left ventricle from the apex of the heart and the right atrial appendage was cut open. Normal saline was perfused with a syringe until the rat's liver changed color. Then, 4% paraformaldehyde universal tissue fixative was continuously perfused until the rat became hard. S102: Cut the rat spinal cord and the vertebral column after the treatment in step S102, soak them in a conventional 4% paraformaldehyde universal tissue fixative I for 24 hours, and then soak them in a new 4% paraformaldehyde universal tissue fixative II for 24 hours; S103: cutting the spinal canal of the rat spinal cord and the spinal column tissue after the immersion treatment in step S102, taking the rat spinal cord out of the spinal column, and fixing the rat spinal cord in 4% paraformaldehyde universal tissue fixative for 24 hours, wherein the volume ratio of the rat spinal cord tissue volume to the 4% paraformaldehyde universal tissue fixative is 1:50; More specifically, the rats were pre-perfused with saline solution by syringe until the rat liver changed color, and then 4% paraformaldehyde universal tissue fixative was continuously perfused to fully clean the shear environment of the rat spinal cord to avoid interference with the sampling caused by the rat's blood and connective tissue.

[0022] In the present invention, step S2 includes: S201: trimming the rat spinal cord tissue after the fixation treatment in step S103, removing the unnecessary tissue, and placing the trimmed rat spinal cord tissue into an embedding box for marking; S202: The rat spinal cord tissue that has been trimmed and marked in step S201 is washed with running water, avoiding direct water flow, and is washed with a small water flow for 12 hours to completely wash away the paraformaldehyde in the rat spinal cord tissue; More specifically, by flushing and immersing the rat spinal cord with a small water flow for 12 hours and flushing with paraformaldehyde, the rat spinal cord can be flushed more cleanly, thus avoiding interference with the subsequent dehydration process.

[0023] In the present invention, before the rat is anesthetized to death in step S101, a pretreatment operation needs to be performed, which specifically includes the following steps: S1001: Ensure that appropriate tools are available: hemostats, tweezers, scissors, and appropriate protective equipment: gloves and goggles; S1002: Use appropriate anesthesia methods to ensure that rats do not feel pain or stress during the sampling process, and avoid stress reactions in rats that may affect the quality of the sampling; S1003: Disinfect the rat surface and the sampling environment to reduce the risk of infection; More specifically, by preparing tools and protective equipment in advance, time wasted during the sampling process, which would affect the quality of the samples. The surface of the mice and the sampling environment were disinfected to ensure the safety of the operators.

[0024] In the present invention, the 95% ethanol solution I immersed in step S304 and the 95% ethanol solution II immersed in step S305 are separately configured, that is, the ethanol solution I and the ethanol solution II are non-reusable ethanol solutions; More specifically, by using ethanol solution I and ethanol solution II as pure ethanol solutions respectively used independently, the efficiency of gradient dehydration is ensured.

[0025] In the present invention, the ethanol I soaked in step S306 and the ethanol II soaked in step S307 are configured separately, that is, ethanol I and ethanol II are non-reusable ethanol; More specifically, ethanol I and ethanol II are independently configured, which can perform more thorough dehydration treatment under high-concentration ethanol conditions, thereby greatly avoiding the situation of residual water.

[0026] In the present invention, the volume ratio of the rat spinal cord and spine tissue volume treated in step S102 to the 4% paraformaldehyde universal tissue fixative is 1:50, and the conventional 4% paraformaldehyde universal tissue fixative I and fixative II configured in step S102 and the conventional 4% paraformaldehyde universal tissue fixative configured in step S103 are configured separately and cannot be reused; More specifically, the stability of sampling and fixation was ensured by using a 1:50 volume ratio of the rat spinal cord and vertebral column tissue volume to 4% paraformaldehyde universal tissue fixative.

[0027] In the present invention, the xylene I configured in step S401 and the xylene II configured in step S402 are both separately configured xylenes, and both xylene I and xylene II cannot be reused; More specifically, by using independently configured xylene I and xylene II for multiple immersion treatments, ethanol can be replaced more fully, thereby avoiding ethanol residue in the specimen.

[0028] In the present invention, the wax liquid I configured in step S501, the wax liquid II configured in step S502, and the wax liquid III configured in step S503 are all separately configured pure wax liquids, and the wax liquids I, II, and III are not reusable; More specifically, by using wax liquids I, II and III, which are separately configured and all are pure wax, for wax immersion treatment, the risk of bubbles in the specimen due to insufficient wax immersion is avoided, thereby ensuring the quality of subsequent sections.

[0029] In the present invention, when the wax liquid III and the tissue soaked therein are embedded in the mold in step S601, the wax liquid needs to be placed together, and the surface of the mold needs to be covered with the wax liquid, and the rat spinal cord tissue is placed according to the required section when placing it; More specifically, by making the surface of the mold covered with wax liquid in step S6, the rat spinal cord tissue is placed according to the required section when inserting, so that the wax liquid can be infiltrated more fully, thereby ensuring the quality of the slices.

[0030] When making paraffin blocks of rat spinal cord tissue: First, ensure that appropriate tools are available: hemostats, tweezers, scissors, and appropriate protective equipment: gloves and goggles. Use appropriate anesthesia methods to ensure that rats do not feel pain or pressure during the sampling process, avoid stress reactions in rats that affect the quality of the sampling, and then disinfect the rat surface and the sampling environment to reduce the risk of infection. Then, perform tissue sampling and fixation. Anesthetize the rat to death and place it in a supine position on the dissecting table. Cut open the rat's chest to expose the heart. Use a syringe needle to insert the left ventricle from the apex of the heart and cut open the right atrial appendage. Use a syringe to perfuse saline until the rat's liver changes color. Then continue to perfuse 4% paraformaldehyde universal tissue fixative until the rat hardens. Then cut the rat's spinal cord together with the spine and soak it in regular 4% paraformaldehyde universal tissue fixative I for 24 hours. Then, the rats were immersed in a new 4% paraformaldehyde universal tissue fixative II for 24 hours, and then the spinal canal of the rat spinal cord and the spinal column tissue after immersion treatment was cut open, the rat spinal cord was taken out from the spinal column, and the rat spinal cord was fixed in a 4% paraformaldehyde universal tissue fixative for 24 hours, and the volume ratio of the rat spinal cord tissue volume to the 4% paraformaldehyde universal tissue fixative was 1:50; Secondly, the sampled tissues were rinsed, the fixed rat spinal cord tissues were trimmed, the unnecessary extra tissues were removed, and the trimmed rat spinal cord tissues were placed in an embedding box for marking, and the trimmed and marked rat spinal cord tissues were washed with running water to avoid direct water flow, and small water flow was used for 12 hours to rinse the paraformaldehyde in the rat spinal cord tissues; The tissues were dehydrated with gradient ethanol again. The washed rat spinal cord group was immersed in 65% ethanol solution for 30 min, immersed in 75% ethanol solution for 30 min, immersed in 85% ethanol solution for 30 min, immersed in 95% ethanol solution I for 30 min, immersed in 95% ethanol solution II for 12 h, immersed in 100% ethanol I for 30 min, and immersed in 100% ethanol II for 60 min. At this time, the sampled tissue was treated with xylene to replace ethanol. The rat spinal cord tissue that had been dehydrated in gradient was immersed in xylene I for 10 minutes, and then taken out and immersed in xylene II for 25 minutes to achieve gradient ethanol replacement. Finally, the tissue was immersed in wax and embedded. The rat spinal cord tissue that had been replaced with xylene was immersed in wax liquid I for 1 hour, taken out and immersed in wax liquid II for 1 hour, and then taken out and immersed in wax liquid III for 1 hour. The wax-immersed rat spinal cord tissue was placed in a tissue embedding mold for 30 minutes, and the mold was placed on a freezing table for 3 seconds to solidify the wax liquid on the surface of the mold and fix the direction and position of the rat spinal cord tissue in the mold. The mold was then filled with wax liquid and placed on a freezing table until the wax was completely solidified. The wax block was then gently removed from the mold, and the wax block could be embedded for long-term storage at room temperature to achieve the preparation of paraffin blocks of rat spinal cord tissue.

[0031] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue, characterized in that: The following steps are involved: S1: tissue sampling and fixation; S2: Rinse the sampled tissue; S3: Dehydration of the sampled tissues with gradient ethanol; S4: The sampled tissue is treated with xylene to replace ethanol; S5: Wax treatment of the sampled tissue; S6: embedding the sampled tissue; The step S3 comprises the following specific steps: S301: the washed rat spinal cord group was placed in a 65% ethanol solution and soaked for 30 minutes; S302: After being taken out in the previous step, the sample is again placed in a 75% ethanol solution and soaked for 30 minutes; S303: After being taken out in the previous step, the sample is again placed in an 85% ethanol solution and soaked for 30 minutes; S304: After being taken out in the previous step, the sample is again placed in 95% ethanol solution I and soaked for 30 minutes; S305: After being taken out in the previous step, it is again placed in 95% ethanol solution II and soaked for 12 hours; S306: After being taken out in the previous step, the sample is again immersed in 100% ethanol I for 30 minutes; S307: After being taken out in the previous step, the sample is again placed in 100% ethanol II and soaked for 60 minutes; The step S4 comprises the following specific steps: S401: placing the rat spinal cord tissue that has been gradient dehydrated in step S3 into xylene I and soaking it for 10 minutes; S402: Take it out again and soak it in xylene II for 25 minutes; The step S5 comprises the following specific steps: S501: placing the rat spinal cord tissue that has been replaced with xylene in step S4 into wax solution I and soaking it for 1 hour; S502: taking out the rat spinal cord tissue soaked in step S501 and soaking it in wax liquid II for 1 hour; S503: taking out the rat spinal cord tissue soaked in step S502 and soaking it in wax solution III for 1 hour; The step S6 comprises the following specific steps: S601: placing the rat spinal cord tissue dipped in wax in step S502 into a tissue embedding mold for 30 minutes, placing the mold on a freezing table for 3 seconds to solidify the wax liquid on the mold surface, and fixing the direction and position of the rat spinal cord tissue in the mold; S602: Fill the mold set in step S601 with wax liquid, place it on a freezing table and wait for the wax to completely solidify, then gently remove the wax block from the mold, and then embed the wax block for long-term storage at room temperature.

2. A dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 1, characterized in that: The step S1 comprises: S101: First, the rat was anesthetized to death and placed in a supine position on a dissecting table. The rat's chest was cut open to expose the heart. A syringe needle was inserted into the left ventricle from the apex of the heart and the right atrial appendage was cut open. Normal saline was perfused with a syringe until the rat's liver changed color. Then, 4% paraformaldehyde universal tissue fixative was continuously perfused until the rat became hard. S102: Cut the rat spinal cord and the vertebral column after the treatment in step S102, soak them in a conventional 4% paraformaldehyde universal tissue fixative I for 24 hours, and then soak them in a new 4% paraformaldehyde universal tissue fixative II for 24 hours; S103: Cut open the vertebral canal of the rat spinal cord and the spinal column tissue after the immersion treatment in step S102, remove the rat spinal cord from the spinal column, and fix the rat spinal cord in 4% paraformaldehyde universal tissue fixative for 24 hours, wherein the volume ratio of the rat spinal cord tissue volume to the 4% paraformaldehyde universal tissue fixative is 1:

50.

3. A dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 2, characterized in that: The step S2 comprises: S201: trimming the rat spinal cord tissue after the fixation treatment in step S103, removing the unnecessary tissue, and placing the trimmed rat spinal cord tissue into an embedding box for marking; S202: The rat spinal cord tissue that has been trimmed and marked in step S201 is washed with running water, avoiding direct water flow, and is rinsed and soaked with a small water flow for 12 hours to rinse away the paraformaldehyde in the rat spinal cord tissue.

4. A dehydration embedding method for preparing a paraffin block of rat spinal cord tissue according to claim 2, characterized in that: Before the rat is anesthetized to death in step S101, a pretreatment operation needs to be performed, which specifically includes the following steps: S1001: Ensure that appropriate tools are available: hemostats, tweezers, scissors, and appropriate protective equipment: gloves and goggles; S1002: Use appropriate anesthesia methods to ensure that rats do not feel pain or stress during the sampling process, and avoid stress reactions in rats that may affect the quality of the sampling; S1003: Disinfect the rat's body surface and the sampling environment to reduce the risk of infection.

5. The dehydration embedding method for preparing a paraffin block of rat spinal cord tissue according to claim 1, characterized in that: The 95% ethanol solution I for soaking in step S304 and the 95% ethanol solution II for soaking in step S305 are configured separately, that is, the ethanol solution I and the ethanol solution II are non-reusable ethanol solutions.

6. The dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 1, characterized in that: The ethanol I soaked in step S306 and the ethanol II soaked in step S307 are configured separately, that is, the ethanol I and ethanol II are non-reusable ethanol.

7. A dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 2, characterized in that: The volume ratio of the rat spinal cord and spine tissue volume treated in step S102 to 4% paraformaldehyde universal tissue fixative is 1:50, and the conventional 4% paraformaldehyde universal tissue fixative I and fixative II configured in step S102 and the conventional 4% paraformaldehyde universal tissue fixative configured in step S103 are configured separately and cannot be reused.

8. The dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 1, characterized in that: The xylene I configured in step S401 and the xylene II configured in step S402 are both separately configured xylenes, and the xylene I and xylene II are not reusable.

9. The dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 1, characterized in that: The wax liquid I configured in step S501, the wax liquid II configured in step S502, and the wax liquid III configured in step S503 are all separately configured pure wax liquids, and the wax liquids I, II, and III are not reusable.

10. The dehydration embedding method for preparing paraffin blocks of rat spinal cord tissue according to claim 1, characterized in that: When the wax liquid III and the tissue soaked therein are embedded in the mold in step S601, the wax liquid needs to be placed together, and the surface of the mold needs to be covered with the wax liquid. When placing the wax liquid, the rat spinal cord tissue is placed according to the required section.

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