A method for preparing cross-sectional specimens of the lungs of patients with viral pneumonia

Abstract

The present invention provides a method for preparing a cross-sectional specimen based on the lungs of a patient with viral pneumonia. In a biosafety autopsy room, the body is placed in a splash-proof autopsy isolation device for processing, and the steps include: 1) dissecting the body to remove the lungs, soaking the lungs in a fixative and then taking them out to obtain a lung specimen; 2) using a spring line method to position the horizontal cross-sectional reference line of titanium dioxide on the surface of the lung specimen, then marking a sawing line, and then freezing the lung specimen; 3) sawing the frozen lung specimen along the sawing line, and verifying it with a CT scan to obtain a cross-sectional specimen; 4) pathologically sampling, cleaning, and brushing the cross-sectional specimen with glue, and then imaging and sealing it. The present invention provides a method for preparing a cross-sectional specimen based on the lungs of a patient with viral pneumonia, which preserves precious clinical pathological data for subsequent research on viral pneumonia and avoids unnecessary infection of operators during the production process.

Description

Technical Field

[0001] The present invention belongs to the field of medical biotechnology and relates to a method for preparing a tomographic specimen based on the lungs of patients with viral pneumonia, and specifically relates to a method for preparing a tomographic specimen based on the lungs of patients with viral pneumonia (especially highly contagious pneumonia, such as novel coronavirus infection, SARS, etc.) for clinical diagnosis, scientific research and teaching. Background Art

[0002] Viral pneumonia, especially highly contagious viral pneumonia, has become an infectious disease that seriously threatens the health and life of the entire human race. In the future, viral pneumonia is likely to become a public health disease that plagues human society for a long time. Therefore, it is necessary for us to preserve as many viral pneumonia case materials as possible and fully study their imaging and pathological conditions in order to lay a solid foundation for a better understanding of this type of infectious disease.

[0003] The progress of medicine is inseparable from pathological anatomy. Pathology can reveal the nature of the disease, including the cause, pathogenesis, and changes and laws of the body's organs, tissues, cells and even molecules during the disease process. It is the foundation of the origin and development of modern medicine. The pathological research results of viral pneumonia obtained by dissection are of great help in understanding the pathological changes and nature of viral pneumonia, revealing the occurrence mechanism and development law, and improving clinical diagnosis and treatment plans. It can also fundamentally find the causes of disease and death of viral pneumonia and provide a basis for the clinical treatment of critically ill patients.

[0004] Pathology is the basis of imaging, and imaging is the manifestation of pathology. The main target organ affected by viral pneumonia is the respiratory system, mainly the lung parenchyma. However, due to the lack of infectious autopsy sample preparation methods that take safety into consideration, there is still a lack of standardized procedures to follow for lung specimens of viral pneumonia. More importantly, the current research and diagnosis of viral pneumonia are mostly in a state of separating pathological morphology from clinical imaging, or only superficially corresponding, and there is a lack of research plans to deeply integrate the two. Therefore, for the lungs of patients who died of viral pneumonia, there is an urgent need to conduct a comparative study that highly integrates clinical imaging and anatomical pathology, establish a viral pneumonia database, and produce clinical research and teaching specimens that integrate clinical anatomy, pathology, and imaging.

[0005] Sectional anatomy is a science that uses the section sawing method to study the morphological structure of the human body. It can accurately present the changes in cross-sectional morphology and the positional proximity of various structures of the body on the basis of maintaining the body structure in situ; it can perform three-dimensional reconstruction and quantitative analysis of the structure by tracing continuous sections or using computers; it is closely combined with imaging diagnosis and interventional radiology, and is the product of the combination of anatomy and medical imaging. Combining section imaging diagnosis and pathological diagnosis of the lungs of patients with viral pneumonia can provide a morphological basis for the teaching, scientific research and imaging diagnosis of such diseases. Summary of the invention

[0006] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a method for preparing a cross-sectional specimen based on the lungs of patients with viral pneumonia. The cross-sectional specimen of the lungs of viral pneumonia prepared by this method can fully meet the clinical diagnosis, teaching and scientific research needs of imaging and pathology, and each cross-sectional specimen achieves the correspondence between imaging data and pathological data; and, since the prepared cross-sectional specimens are clean and tidy and are fully fixed with neutral formalin, they can be preserved for a long time, which is not only intuitive and vivid when used for teaching, scientific research and clinical imaging diagnosis, but also can preserve precious clinical pathological data for future human research on viral pneumonia.

[0007] To achieve the above-mentioned and other related purposes, the present invention provides, in a first aspect, a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein the body is placed in a splash-proof autopsy isolation device in a biosafety autopsy room for processing, comprising the following steps:

[0008] 1) The lungs are removed from the corpse by dissection, and the lungs are taken out after being immersed in a fixative to obtain a lung specimen;

[0009] 2) using the elastic line method to position the horizontal cross-sectional reference line of the titanium dioxide dye on the surface of the lung specimen obtained in step 1), and then cutting the line with a saw, and then freezing the lung specimen;

[0010] 3) sawing the lung specimen frozen in step 2) along the sawing line, and verifying it by CT scanning to obtain a cross-sectional specimen;

[0011] 4) The cross-sectional specimen obtained in step 3) is pathologically sampled, cleaned, glued, imaged, and sealed.

[0012] Preferably, the body is placed in a splash-proof autopsy isolation device for processing, comprising the following steps:

[0013] a) The splash-proof autopsy isolation device comprises a pollution source chamber and a semi-clean chamber separated by an isolation surface. The curtain door on the side of the pollution source chamber adjacent to the isolation surface is opened to place the corpse in the pollution source chamber. After closing the curtain door, the corpse is dissected and the lungs are removed through at least one first operation port provided on the other side adjacent to the isolation surface and / or at least one second operation port provided on the side opposite to the isolation surface.

[0014] b) A second isolation curtain is provided on the side of the semi-clean chamber opposite to the isolation surface, and the lungs are transferred from the pollution source chamber to the semi-clean chamber through the first isolation curtain provided on the isolation surface through at least one third operation port provided on the second isolation curtain;

[0015] c) placing the lung in a specimen storage container provided in a semi-clean chamber, soaking the lung in a fixative to obtain a lung specimen, then sawing the lung specimen, opening the second isolation curtain, taking out the lung specimen and freezing it;

[0016] d) placing the frozen lung specimen into the semi-clean chamber through the second isolation curtain, sawing through the third operation port to obtain a cross-sectional specimen, and performing pathological sampling, cleaning, brushing glue and sealing on the cross-sectional specimen, and then taking it out through the second isolation curtain for imaging processing;

[0017] e) The image-processed cross-sectional specimen is placed in a semi-clean chamber through a second isolation curtain to prepare a specimen box and then taken out.

[0018] Preferably, the splash-proof autopsy isolation device includes adjacent pollution source chambers and semi-clean chambers, the pollution source chambers and the semi-clean chambers are isolated from each other by an isolation surface, and a first isolation curtain is provided on the isolation surface; on the pollution source chamber, a side surface adjacent to the isolation surface is a curtain door, and at least one first operating port is provided on the other side surface adjacent to the isolation surface, and at least one second operating port is provided on the side opposite to the isolation surface; on the semi-clean chamber, a second isolation curtain is provided on the side opposite to the isolation surface, and at least one third operating port is provided on the second isolation curtain.

[0019] More preferably, a top plate is provided on the top of the pollution source chamber, and a plurality of support rods are provided below the top plate.

[0020] Further preferably, four support rods are provided below the top plate.

[0021] More preferably, the first isolation lifting curtain, the second isolation lifting curtain and the curtain door are upper-opening and closable structures.

[0022] More preferably, there are two first operating ports and / or two second operating ports.

[0023] More preferably, there are two third operating ports.

[0024] More preferably, the first operating port, the second operating port and the third operating port are provided with operating gloves with sealing interfaces.

[0025] More preferably, a specimen storage container is provided in the semi-clean chamber.

[0026] Preferably, in step 1), the corpse is a corpse of a patient with viral pneumonia, including but not limited to novel coronavirus infection or SARS.

[0027] Preferably, in step 1), before the corpse is placed in the splash-proof autopsy isolation device, the hair of the corpse needs to be shaved, dirt and oil stains on the skin of the corpse need to be removed, and the corpse needs to be shaped with a bandage after being disinfected with a disinfectant.

[0028] More preferably, the disinfectant is an ethanol aqueous solution with a volume percentage of 70-80%. Most preferably, the disinfectant is an ethanol aqueous solution with a volume percentage of 75%.

[0029] More preferably, the cadaver shaping is performed in an anatomical posture.

[0030] Preferably, in step 1), the lungs are removed by dissecting the body's trachea, opening the chest cavity using a T-shaped incision, removing the sternum and costal cartilage to expose the chest cavity, and then cutting the arteries, trachea, lung roots and pulmonary ligaments to remove the lungs.

[0031] Preferably, in step 1), the lungs are immersed in the fixative by firstly injecting the fixative into the lungs through the opening of the tracheal stump, and then immersing the lungs filled with the fixative in the fixative.

[0032] More preferably, the fixing solution is a 5-15% neutral formalin solution. Most preferably, the fixing solution is a 10% neutral formalin solution.

[0033] More preferably, the lungs are immersed in the fixative for 46-50 hours.

[0034] Preferably, in step 1), the fixative is poured out from the lung specimen, the specimen is rinsed with clean water, the water on the surface of the lung specimen is absorbed, and the specimen is then left to dry.

[0035] More preferably, the moisture on the surface of the lung specimen is absorbed by absorbent filter paper.

[0036] More preferably, the step of standing and air-drying is placing the lung specimen, from which surface moisture has been absorbed, on absorbent filter paper and standing in a cool, dark place for 4-6 hours to dry.

[0037] Preferably, in step 2), the horizontal cross-section reference line is positioned with the longitudinal axis of the trachea as the coronal line, and the line perpendicular to it is drawn as the transverse line.

[0038] Preferably, in step 2), the titanium white dye is titanium dioxide.

[0039] Preferably, in step 2), the scribing depth of the sawing line is 1-2 cm.

[0040] Preferably, in step 2), the lung specimen is sealed before freezing.

[0041] Preferably, in step 2), the freezing is to freeze the lung specimen at ≤-30°C for 4-6 days.

[0042] Preferably, in step 3), the lung specimen needs to be fixed before sawing, and the lung specimen should be fixed on a band saw.

[0043] Preferably, in step 3), the sawing is performed using a band saw.

[0044] More preferably, the sawing loss of the band saw machine is less than 2 mm.

[0045] More preferably, on the band saw machine, the distance between the fixed baffle and the saw blade is equal to the thickness of the lung specimen to be sawed plus half of the sawing loss.

[0046] Preferably, in step 3), the thickness of the tomographic specimen is consistent with the scanning thickness of CT.

[0047] More preferably, the thickness of the tomographic specimen and the scanning thickness of CT are both 0.7-0.9 mm.

[0048] Preferably, in step 4), the pathological sampling comprises the following steps:

[0049] A) Observe the pathological changes of the cross-section specimens at room temperature, and take the lesion tissue for examination if there are morphological changes in the lesion area;

[0050] B) The sampled lesion tissues were sequentially subjected to gradient alcohol dehydration, xylene clearing, paraffin immersion, paraffin embedding, pathological tissue sectioning, slide attachment, tissue section xylene dewaxing, HE staining, gradient alcohol dehydration, xylene clearing, and gum sealing to obtain HE stained sections.

[0051] More preferably, in step A), the pathological changes are selected from one or more of color, texture, consolidation, and mucoid changes.

[0052] Preferably, in step 4), the cleaning is rinsing with water.

[0053] Preferably, in step 4), after cleaning, the moisture on the surface of the section specimen is dried and then allowed to stand and dry.

[0054] More preferably, the moisture on the surface of the section specimen is absorbed by absorbent filter paper.

[0055] More preferably, the step of standing and drying is to place the section specimen, from which surface moisture has been absorbed, on absorbent filter paper and stand in a cool, dark place for 4-6 hours to dry.

[0056] Preferably, in step 4), the brushing of glue is to use gelatin liquid to brush the surface of the section specimen, and then let it stand to dry.

[0057] More preferably, the gelatin solution is obtained by hydrolysis of collagen.

[0058] More preferably, the concentration of the gelatin solution is 15-25%.

[0059] More preferably, the gelatin solution is applied 1-3 times.

[0060] More preferably, the drying is performed in a cool and dark place.

[0061] Preferably, in step 4), the imaging process is to scan the two cross sections of the cleaned and glued cross-section specimens with a scanner and store them in a computer hard disk.

[0062] Preferably, in step 4), the sealing is to place the cleaned and glued section specimens in a specimen box filled with a preservation solution for permanent sealing.

[0063] More preferably, the preservation solution is 4-6% neutral formalin solution.

[0064] More preferably, the specimen box is a specimen box made of polymethyl methacrylate plate.

[0065] The second aspect of the present invention provides the use of the above method in preparing cross-sectional specimens of the lungs of patients with viral pneumonia.

[0066] As described above, the method for preparing a cross-sectional specimen based on the lungs of patients with viral pneumonia provided by the present invention has the following beneficial effects:

[0067] (1) The cross-sectional specimens of viral pneumonia lungs prepared by the method of the present invention can fully meet the clinical diagnosis, teaching and scientific research needs of both imaging and pathology. Each cross-sectional specimen achieves the correspondence between imaging data and pathological data.

[0068] (2) The cross-sectional specimens of the lungs of viral pneumonia prepared by the method of the present invention are clean and tidy, and can be fully fixed with neutral formalin for long-term preservation, thereby preserving precious clinical pathological data for subsequent research on viral pneumonia.

[0069] (3) The preparation process of the viral pneumonia lung cross-sectional specimen prepared by the method of the present invention fully considers the infectiousness of viral pneumonia, has a significant protective effect, and avoids unnecessary infection of the operator during the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 Shown is a schematic diagram of the overall structure of a splash-proof autopsy isolation device in the present invention.

[0071] Figure 2 Shown is an anatomical structure diagram of a cross-sectional specimen of the lung of a viral pneumonia patient prepared according to the present invention.

[0072] Figure 3 Shown is a HE-stained section image of a cross-sectional specimen of the lung of a patient with interstitial pneumonia prepared according to the present invention.

[0073] Figure 4 Shown is a HE-stained section image of a lung section specimen based on a critically ill viral pneumonia patient prepared according to the present invention.

[0074] Reference numerals

[0075] 1 Pollution source chamber

[0076] 2 Semi-clean chamber

[0077] 3. First isolation curtain

[0078] 4 Curtain Door

[0079] 5 First operation port

[0080] 6 Second operation port

[0081] 7 Second isolation curtain

[0082] 8 Third operation port

[0083] 9 Operating gloves

[0084] 10 Top Plate

[0085] 11 Support rod

[0086] 12 Specimen storage container DETAILED DESCRIPTION

[0087] The present invention is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention.

[0088] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0089] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art; all pressure values ​​and ranges refer to relative pressures.

[0090] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0091] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia. In a biosafety autopsy room, a corpse is placed in a splash-proof autopsy isolation device for processing, comprising the following steps:

[0092] 1) In a biosafety autopsy room, the body is placed in a splash-proof autopsy isolation device for processing, the lungs are removed by dissection, and the lungs are taken out after being immersed in a fixative to obtain a lung specimen;

[0093] 2) using the elastic line method to position the horizontal cross-sectional reference line of the titanium dioxide dye on the surface of the lung specimen obtained in step 1), and then cutting the line with a saw, and then freezing the lung specimen;

[0094] 3) sawing the lung specimen frozen in step 2) along the sawing line, and verifying it by CT scanning to obtain a cross-sectional specimen;

[0095] 4) The cross-sectional specimen obtained in step 3) is pathologically sampled, cleaned, glued, imaged, and sealed.

[0096] The above-mentioned biosafety autopsy room is a routinely used autopsy room that meets the requirements for biosafety autopsy operations. The biosafety autopsy room can perform negative pressure filtration, is equipped with a dedicated operating table, and should also have showers or sanitary facilities, air conditioning or heating and cooling equipment, and a dedicated sewage treatment system.

[0097] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, the corpse is placed in a splash-proof autopsy isolation device for processing, comprising the following steps:

[0098] a) The splash-proof autopsy isolation device comprises a pollution source chamber and a semi-clean chamber separated by an isolation surface. The curtain door on the side of the pollution source chamber adjacent to the isolation surface is opened to place the corpse in the pollution source chamber. After closing the curtain door, the corpse is dissected and the lungs are removed through at least one first operation port provided on the other side adjacent to the isolation surface and / or at least one second operation port provided on the side opposite to the isolation surface.

[0099] b) A second isolation curtain is provided on the side of the semi-clean chamber opposite to the isolation surface, and the lungs are transferred from the pollution source chamber to the semi-clean chamber through the first isolation curtain provided on the isolation surface through at least one third operation port provided on the second isolation curtain;

[0100] c) placing the lung in a specimen storage container provided in a semi-clean chamber, soaking the lung in a fixative to obtain a lung specimen, then sawing the lung specimen, opening the second isolation curtain, taking out the lung specimen and freezing it;

[0101] d) placing the frozen lung specimen into the semi-clean chamber through the second isolation curtain, sawing through the third operation port to obtain a cross-sectional specimen, and performing pathological sampling, cleaning, brushing glue and sealing on the cross-sectional specimen, and then taking it out through the second isolation curtain for imaging processing;

[0102] e) The image-processed cross-sectional specimen is placed in a semi-clean chamber through a second isolation curtain to prepare a specimen box and then taken out.

[0103] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, the splash-proof autopsy isolation device, such as Figure 1As shown, it includes adjacent pollution source chambers and semi-clean chambers, the pollution source chambers and the semi-clean chambers are isolated from each other by an isolation surface, and a first isolation curtain is provided on the isolation surface; on the pollution source chamber, a side surface adjacent to the isolation surface is a curtain door, and on the other side surface adjacent to the isolation surface is at least one first operating port, and on the side opposite to the isolation surface is at least one second operating port; on the semi-clean chamber, a second isolation curtain is provided on the side opposite to the isolation surface, and at least one third operating port is provided on the second isolation curtain.

[0104] The pollution source chamber and semi-clean chamber are made of transparent plastic film. Since the pathological autopsy operation takes a long time and the exposed area of ​​the visceral tissue section is large, it is necessary to use a transparent plastic film with good light transmittance and the ability to withstand repeated folding to be suitable for the pathological autopsy scene.

[0105] In a preferred embodiment, Figure 1 As shown, the top of the pollution source chamber is provided with a top plate, and a plurality of support rods are provided under the top plate. The support rods are used to support the pollution source chamber and drive and support the semi-clean chamber at the same time, forming enough space for the corpse to be stored in the pollution source chamber and processed and prepared in the semi-clean chamber.

[0106] Specifically, four support rods are arranged under the top plate, so that the pollution source chamber can be supported relatively stably and maintain sufficient space.

[0107] The top plate and the support rod are made of transparent hard plastic and have a certain supporting capacity.

[0108] In a preferred embodiment, Figure 1 As shown, the first isolation curtain, the second isolation curtain and the curtain door are upper opening and closing structures. The openings of the first isolation curtain, the second isolation curtain and the curtain door are opened from bottom to top.

[0109] The first isolation curtain can block the aerosol and body fluid generated during the autopsy from splashing into the semi-clean chamber. At the same time, opening the first isolation curtain can transfer the human specimen obtained after the autopsy to the semi-clean chamber for subsequent processing.

[0110] The second isolation curtain can block the possible situation that the fixative splashes outside the isolation device when the human specimen is stored in the fixative. At the same time, the human specimen stored in the fixative can be transferred to other places by opening the second isolation curtain.

[0111] The openable curtain door can be opened to place the corpse.

[0112] In a preferred embodiment, Figure 1As shown, the number of the first operation openings 5 ​​and / or the second operation openings 6 are both two, so that the operator can operate the corpse in the contamination source chamber with both hands.

[0113] In a preferred embodiment, Figure 1 As shown, there are two third operation ports, which facilitates the operator to operate the human specimen in the semi-clean chamber with both hands.

[0114] In a preferred embodiment, Figure 1 As shown, the semi-clean chamber is provided with a specimen storage container. The specimen storage container is a sealed tank filled with a fixative, which can prevent the cut human specimen from becoming a source of contamination during the moving process.

[0115] In a preferred embodiment, Figure 1 As shown, the first operation port, the second operation port and the third operation port are provided with operation gloves with sealing interfaces. The operation gloves can facilitate the operator to dissect the human specimen in the contamination source chamber and / or the semi-clean chamber, thereby preventing the contamination source in the contamination source chamber and / or the semi-clean chamber from contacting the operator. At the same time, when the dissection operation is not performed, the first operation port, the second operation port and the third operation port can be closed.

[0116] In a preferred embodiment, Figure 1 As shown, a specimen storage container is provided in the semi-clean chamber. The specimen storage container is a sealed can filled with a fixative and can be used to store the lungs. This can prevent the human specimen from becoming a source of contamination during movement.

[0117] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein the corpse is a corpse of a patient with viral pneumonia. The viral pneumonia includes but is not limited to novel coronavirus infection or SARS.

[0118] The present invention provides a method for preparing a cross-sectional specimen of the lungs of a patient with viral pneumonia. Before the corpse is placed in a splash-proof autopsy isolation device, the hair of the corpse needs to be shaved, dirt and oil stains on the skin of the corpse need to be removed, and the corpse needs to be disinfected with a disinfectant before being shaped with a bandage.

[0119] In a preferred embodiment, the disinfectant is an ethanol aqueous solution with a volume percentage of 70-80%, preferably an ethanol aqueous solution with a volume percentage of 75%, so as to have the best bactericidal effect.

[0120] In a preferred embodiment, the cadaver is shaped in an anatomical posture.

[0121] The present invention provides a method for preparing a cross-sectional specimen of the lungs of a patient with viral pneumonia. In step 1), the lungs are removed by dissecting the body's trachea, opening the chest cavity using a T-shaped incision, removing the sternum and costal cartilage to expose the chest cavity, and then cutting off the arteries, trachea, lung roots and pulmonary ligaments to remove the lungs.

[0122] In a specific embodiment, the sternum and costal cartilage are removed by incising the chest cavity, peeling off the extrathoracic tissue, exposing the ribs, using a cartilage knife to cut the costal cartilage on both sides starting from the second rib, then using a scalpel to cut the sternoclavicular joint, using rib scissors to cut the first ribs on both sides, lifting the costal arch, placing it close to the back of the sternum and costal cartilage, and removing it after dividing the diaphragm and mediastinum.

[0123] When the costal cartilages on both sides are cut starting from the second rib, the distance between the tangent line and the junction of the costal cartilage and the rib is 0.5-1 cm.

[0124] In a specific embodiment, the artery and trachea are cut by cutting the innominate artery and the left subclavian artery, and the trachea is cut 3-4 cm above the tracheal bifurcation at the section of the thoracic costal cartilage using a scalpel.

[0125] In a specific embodiment, when cutting off the lung root and the pulmonary ligament, the lung should be separated from the mediastinum, the blood vessels and nerves around the lung root should be avoided, and the lung root and the pulmonary ligament should be cut vertically. After removing the lung, pay attention to the position and integrity of the bronchi, pulmonary arteries, pulmonary veins, bronchial arteries and bronchohilar lymph nodes at the hilum. Pay special attention to the phrenic nerve and pericardial phrenic vessels in front of the left lung root and the vagus nerve in the back; the accessory nerve and pericardial phrenic vessels in front of the right lung root, the vagus nerve in the back, and the azygos vein arch above, which should be avoided.

[0126] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia. In step 1), the lung is immersed in a fixative by first injecting the fixative into the lung through the opening of the tracheal stump, and then immersing the lung filled with the fixative in the fixative.

[0127] In a preferred embodiment, the fixing solution is a 5-15% neutral formalin solution, preferably a 10% neutral formalin solution.

[0128] In a preferred embodiment, the lungs are immersed in the fixative for 46-50 hours, preferably 48 hours.

[0129] When the fixative is injected into the lungs, the trachea needs to be cut off at about 5 cm from the bifurcation of the trachea. A disposable infusion set plastic tube wrapped with gauze strips is inserted into the broken end of the trachea so that the outer end is aligned with the broken end of the trachea. Gauze is placed between the plastic tube and the inner wall of the trachea, and then the suture is tied around the outside of the trachea. Use a syringe to absorb the fixative and inject it slowly in batches from the center of the plastic tube. If there is gas in the trachea during the injection process, the lung should be gently lifted, and the syringe should be pulled out at the same time. The lung should be slowly lowered to allow the gas to discharge. When the fixative is about to flow out, the syringe should be inserted and injected again. The amount injected should be such that it cannot be injected. Do not apply too much pressure during injection to prevent the tube wall from rupturing. If leakage is found, pinch it with hemostatic forceps or tie it with thread.

[0130] When the lungs filled with fixative are immersed in the fixative, the upper end of the lungs (i.e. the tracheal stump) is fixed above the plastic bucket to maintain a normal anatomical position.

[0131] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia. In step 1), the fixative is poured out of the lung specimen, the specimen is rinsed with clean water, the water on the surface of the lung specimen is absorbed, and the specimen is left to dry.

[0132] In a preferred embodiment, the moisture on the surface of the lung specimen is absorbed by absorbent filter paper.

[0133] In a preferred embodiment, the standing and air-drying step is to place the lung specimen, which has been dried of surface moisture, on a water-absorbing filter paper and stand it in a cool and dark place for 4-6 hours to dry. During this period, the water-absorbing filter paper should be replaced in time, and the condition of the lung specimen during air-drying should be carefully observed, and attention should be paid to maintaining a certain degree of moisture in the lung tissue but not being too dry.

[0134] In the method for preparing a tomographic specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 2), the horizontal cross-section reference line is positioned with the longitudinal axis of the trachea as the coronal line, and the line perpendicular to the trachea is drawn as the transverse line, so as to ensure that the marking line of the tomographic specimen is consistent with the cross-section positioning line of the longitudinal axis of the lung.

[0135] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 2), the line-snapping method is a conventional method in the art. Specifically, a line dipped in titanium dioxide is used, and two people each hold one end and then flick it on the surface of the lung tissue, which is actually using the line to replace the pen and titanium dioxide to replace the ink to locate the horizontal cross-sectional reference line of the specimen surface.

[0136] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein in step 2), the titanium white dye is titanium dioxide.

[0137] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein in step 2), the scribing depth of the sawing line is 1-2 cm.

[0138] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 2), the lung specimen is sealed before freezing to prevent infection.

[0139] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein in step 2), the freezing is to freeze the lung specimen at ≤-30°C for 4-6 days, preferably at -30°C for 5 days.

[0140] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 3), the lung specimen needs to be fixed before sawing. Specifically, the lung specimen should be fixed on a band saw. Specifically, the lung specimen is fixed on a fixed baffle of the band saw.

[0141] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 3), the sawing is performed by a band saw. The band saw is a conventionally used joinery band saw. Specifically, the band saw is a MJ345E joinery band saw.

[0142] In a preferred embodiment, the sawing loss of the band saw machine is less than 2 mm. The band saw machine adjusts the tension of the saw blade according to the different parts of the lung specimen to be sawed.

[0143] In a preferred embodiment, on the band saw machine, the distance between the fixed baffle and the saw blade is equal to the thickness of the lung specimen to be sawed plus half of the sawing loss.

[0144] The present invention provides a method for preparing a tomographic specimen based on the lungs of a patient with viral pneumonia. In step 3), the thickness of the tomographic specimen is consistent with the scanning thickness of CT.

[0145] In a preferred embodiment, the thickness of the tomographic specimen and the scanning thickness of CT are both 0.7-0.9 mm, preferably 0.8 mm.

[0146] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 3), the length and width of the cross-sectional specimen should be carefully measured and recorded one by one, and the cross-sectional specimen should be placed in a plastic bag, and the plastic bag should be marked with a waterproof oil pen, and then placed in a -30°C medical freezer in order for temporary storage. It should not be placed in a high temperature environment for too long to prevent the specimen from being damaged.

[0147] The present invention provides a method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia, wherein in step 4), the pathological sampling comprises the following steps:

[0148] A) Observe the pathological changes of the cross-section specimens at room temperature, and take the lesion tissue for examination if there are morphological changes in the lesion area;

[0149] B) The sampled lesion tissues were sequentially subjected to gradient alcohol dehydration, xylene clearing, paraffin immersion, paraffin embedding, pathological tissue sectioning, slide attachment, tissue section xylene dewaxing, HE staining, gradient alcohol dehydration, xylene clearing, and gum sealing to obtain HE stained sections.

[0150] In a preferred embodiment, in step A), the pathological changes include but are not limited to color, texture, consolidation, mucoid changes, etc.

[0151] In step B), the above-mentioned steps of gradient alcohol dehydration, xylene transparency, paraffin wax immersion, paraffin embedding of sampled tissue, pathological tissue sectioning, slide attachment, tissue section xylene dewaxing, HE staining, gradient alcohol dehydration, xylene transparency, and gum sealing are all conventional treatment methods for lesion tissue. For details, refer to Chapter 4 "Slice Preparation and Staining Technology" in "Modern Experimental Pathology Technology" (Military Medical Science Press, 1st edition, August 2012, editors-in-chief: Peng Ruiyun, Li Yang, deputy editors-in-chief: Gao Yabing, Liu Chao, chief examiner: Wang Dewen).

[0152] In step B), the HE-stained sections are used to observe pathological histological changes under a microscope.

[0153] The present invention provides a method for preparing a cross-sectional specimen based on the lungs of patients with viral pneumonia, wherein in step 4), the cleaning is flushing with water.

[0154] The present invention provides a method for preparing a cross-sectional specimen of the lungs of a patient with viral pneumonia, wherein in step 4), after the cleaning, moisture on the surface of the cross-sectional specimen is absorbed and then the specimen is allowed to stand and dry.

[0155] In a preferred embodiment, the moisture on the surface of the section specimen is absorbed by absorbent filter paper.

[0156] In a preferred embodiment, the drying step is to place the section specimen, which has been dried of surface moisture, on a water-absorbing filter paper and leave it in a cool and dark place for 4-6 hours to dry. During this period, the water-absorbing filter paper should be replaced in a timely manner.

[0157] The present invention provides a method for preparing a cross-sectional specimen of the lungs of a patient with viral pneumonia, wherein in step 4), the brushing of glue is to use gelatin liquid to brush the surface of the cross-sectional specimen, and then let it stand to dry.

[0158] In a preferred embodiment, the concentration of the gelatin solution is 15-25%, preferably 20%.

[0159] In a preferred embodiment, the gelatin solution is applied 1-3 times, preferably 2 times.

[0160] The gelatin solution is obtained by hydrolyzing collagen. The collagen (collagen for short) is the most important protein component in the skin and bones of animals. Applying gelatin solution on the surface of the section specimen can isolate air and stabilize the tissue morphology.

[0161] In a preferred embodiment, the drying is drying in a cool and dark place.

[0162] In the method for preparing a cross-sectional specimen of the lung of a patient with viral pneumonia provided by the present invention, in step 4), the imaging process is to scan two cross sections of the cleaned and glued cross-sectional specimen with a scanner and store them in a computer hard disk as permanent scientific research data.

[0163] In the method for preparing a cross-sectional specimen based on the lungs of patients with viral pneumonia provided by the present invention, in step 4), the sealing is to place the cleaned and glued cross-sectional specimen in a specimen box containing a preservation solution for permanent sealing.

[0164] In a preferred embodiment, the preservation solution is a 4-6% neutral formalin solution, preferably a 5% neutral formalin solution.

[0165] In a preferred embodiment, the specimen box is a specimen box made of a polymethyl methacrylate plate. The specimen box is made of a transparent polymethyl methacrylate plate, and the joint surface is connected with chloroform. A small hole is drilled on the side of the specimen box with an electric drill as an injection hole for injection of medicine for corrosion prevention. The washed and glued fault specimen is placed in the specimen box, and the upper cover is added. The preservation liquid is injected through the side injection hole, and then the injection hole is blocked for preservation. Note that the connection between the joint surface and the injection hole must be tight to avoid damage and water leakage in the future.

[0166] Example 1

[0167] In a biosafety autopsy room with negative pressure filtration that meets operational requirements, the hair of the bodies of patients with viral pneumonia was shaved, dirt and oil stains on the skin of the bodies were removed, and after disinfection with 75% ethanol aqueous solution, the bodies were bandaged and fixed in anatomical posture.

[0168] Open the curtain door of the upper opening type openable and closable structure on one side of the pollution source chamber of the splash-proof autopsy isolation device, put the stereotyped viral pneumonia patient's body into the pollution source chamber, and close the curtain door. The operator extends his hand into the pollution source chamber through the operating gloves of the sealing interface on the first operating port and / or the second operating port, and performs pathological dissection on the body. First, the trachea of ​​the viral pneumonia patient's body is cut off, the chest cavity is cut open by T-shaped incision method, the extrathoracic tissue is peeled off, the ribs are exposed, and the costal cartilage on both sides is cut off from the second rib with a cartilage knife. The tangent is 0.75cm from the junction of the costal cartilage and the ribs, and then the sternoclavicular joint is cut off with a scalpel, and the first ribs on both sides are cut off with rib scissors. The costal arch is lifted and placed close to the back of the sternum and costal cartilage. After the diaphragm and mediastinum are divided, the sternum and costal cartilage are removed to expose the chest cavity. Then the innominate artery and the left subclavian artery are cut off, and the trachea is cut off 3.5cm above the tracheal bifurcation at the cross section of the thoracic costal cartilage with a scalpel. Then separate the lung from the mediastinum, avoid the blood vessels and nerves around the lung root, vertically cut the lung root and pulmonary ligament, and remove the lung. After removing the lung, pay attention to the location and integrity of the bronchi, pulmonary arteries, pulmonary veins, bronchial arteries, and bronchohilar lymph nodes at the hilum. Pay special attention to the phrenic nerve and pericardial phrenic vessels in front of the left lung root and the vagus nerve behind; the accessory nerve and pericardial phrenic vessels in front of the right lung root, the vagus nerve behind, and the azygos vein arch above, which should be avoided.

[0169] Then, the operator reaches into the semi-clean chamber through the operating glove with a sealed interface on the third operating port, lifts the first isolation curtain, transfers the lungs removed from the contamination source chamber to the specimen storage container in the semi-clean chamber, and closes the first isolation curtain.

[0170] Preserve the lungs in the specimen storage container. First, inject 10% neutral formalin solution into the lungs through the opening of the tracheal stump. Cut the trachea about 5 cm away from the bifurcation of the trachea. Insert the plastic tube of a disposable infusion set wrapped with gauze into the stump of the trachea so that the outer end is aligned with the stump of the trachea. Put gauze between the plastic tube and the inner wall of the trachea, and then tie it tightly with sutures around the outside of the trachea. Use a syringe to absorb 10% neutral formalin solution and inject it slowly in batches from the center of the plastic tube. If there is gas in the trachea during the perfusion process, the lungs should be gently lifted, and the syringe should be pulled out at the same time. The lungs should be slowly lowered to let the gas out. When you see that the 10% neutral formalin solution is about to flow out, insert the syringe again to perfuse. The amount of injection should be such that it cannot be injected. Do not apply too much pressure during injection to prevent the tube wall from rupturing. If leakage is found, pinch it with hemostatic forceps or tie it with thread.

[0171] Then, the lungs filled with 10% neutral formalin solution were soaked in the 10% neutral formalin solution in the specimen storage container for 48 hours and then taken out to obtain the lung specimens. During the soaking, the upper end of the lungs (i.e., the tracheal stump) was fixed above the plastic bucket to maintain the normal anatomical position. The soaked lung specimens were taken out and the 0% neutral formalin solution was poured out. After rinsing with clean water, the surface moisture of the lung specimens was absorbed with absorbent filter paper. The surface moisture of the lung specimens was absorbed and placed on the absorbent filter paper. The lung specimens were left to dry in a cool and dark place in the splash-proof autopsy isolation device for 5 hours. The condition of the lung specimens during drying was carefully observed, and it was noted that the lung tissues should be kept moist but not too dry.

[0172] The titanium dioxide powder used as titanium white dye was positioned on the surface of the lung specimen by the elastic line method. The longitudinal axis of the trachea was used as the coronal line, and the line perpendicular to it was used as the transverse line. The saw cut line was made at a depth of 1.5 cm, and then the lung specimen was sealed. The operator extended his hand through the operating glove of the sealing interface on the third operating port, lifted the second isolation curtain, took out the sealed lung specimen, and frozen it at -30°C for 5 days.

[0173] The operator lifts the second isolation curtain, places the frozen lung specimen into the semi-clean chamber, and places the MJ345E joinery band saw into the semi-clean chamber, and closes the second isolation curtain. The operator reaches into the semi-clean chamber through the operating gloves of the sealing interface on the third operating port, fixes the lung specimen on the fixed baffle of the band saw, and uses the joinery band saw to saw along the sawing line to obtain the cross-sectional specimen. The sawing loss of the joinery band saw is less than 2 mm, and the distance between the fixed baffle and the saw blade of the joinery band saw is equal to the thickness of the lung specimen to be sawed plus half of the sawing loss. When sawing, CT scanning should be used for verification. The thickness of the cross-sectional specimen is consistent with the scanning thickness of CT, both of which are 0.8 mm. The length and width of the cross-sectional specimen should be carefully measured and recorded one by one. The cross-sectional specimen should be placed in a sealed bag, and the sealed bag should be marked with a waterproof oil pen. The operator can extend his hand through the operating glove of the sealing interface on the third operating port, lift the second isolation curtain, take out the sealed fault specimens, and put them into a -30°C medical freezing freezer in order for temporary storage.

[0174] The operator can also extend his hand into the semi-clean chamber through the operating gloves on the sealing interface of the third operating port to continue the pathological sampling. That is, the pathological changes of the section specimens are first observed at room temperature. For the lesion area with morphological changes, the lesion tissue should be sampled. The pathological changes include but are not limited to color, texture, consolidation, mucus change, etc. The sampled lesion tissue is sequentially subjected to gradient alcohol dehydration, xylene transparency, paraffin immersion, paraffin embedding of sampled tissue, pathological tissue sectioning, slide attachment, tissue section xylene dewaxing, HE staining, gradient alcohol dehydration, xylene transparency, and gum sealing to obtain HE stained sections for observation of pathological histological changes under a microscope.

[0175] After the pathological specimen is washed with water, the surface water of the specimen is dried with absorbent filter paper, and the specimen with the surface water dried is placed on the absorbent filter paper and left to dry in a cool and dark place for 4-6 hours. During this period, the absorbent filter paper should be replaced in time. Then, the surface of the specimen is brushed twice with 20% gelatin solution obtained by hydrolyzing collagen, and then left to dry in a cool and dark place of the splash-proof autopsy isolation device, and sealed with a transparent bag.

[0176] The operator extends his hand through the operating glove of the sealing interface on the third operating port, lifts the second isolation curtain, takes out the sealed fault specimen, scans the two sections of the fault specimen separately with a scanner, and stores them in the computer hard disk as permanent scientific research data.

[0177] Finally, lift the second isolation curtain, put the sealed fault specimen into the semi-clean chamber, and close the second isolation curtain. The operator extends his hand into the semi-clean chamber through the operating glove of the sealing interface on the third operating port, removes the seal of the fault specimen, and puts it into a specimen box made of a transparent polymethyl methacrylate plate. Connect the joint surface with chloroform (chloroform), drill a small hole on the side of the specimen box with an electric drill as an injection hole, put the fault specimen into the specimen box, seal the upper cover, inject 5% neutral formalin solution through the side injection hole, and then seal the injection hole for storage. Note that the connection between the joint surface and the injection hole must be tight to avoid damage and leakage in the future. The operator extends his hand through the operating glove of the sealing interface on the third operating port, lifts the second isolation curtain, and transfers the specimen box containing the fault specimen to a place for long-term storage. In the above process, the splash-proof autopsy isolation device ensures that the pollution source does not directly contact the operator.

[0178] The fault specimen prepared in the present invention is as follows: Figure 2 As shown, its anatomical structure is clear and the lesion display is high, which can well meet the needs of gross observation.

[0179] The cross-sectional specimens prepared in the present invention can be verified by HE staining sections:

[0180] like Figure 3 As shown, in the HE-stained sections of the cross-section specimen, the pulmonary interstitium is congested and edematous, with infiltration of lymphocytes and monocytes, resulting in widening of some alveolar septa, and no exudate or only a small amount of serous fluid in the alveolar cavity. This shows that the appearance of the cross-section specimen under the microscope is consistent with interstitial pneumonia, and it belongs to the lungs of patients with interstitial pneumonia among patients with viral pneumonia.

[0181] For example Figure 4As shown in the figure, in addition to the involvement of the pulmonary interstitium, the HE-stained sections of the cross-section specimens also involve the alveolar cavity, where varying amounts of serous fluid, cellulose, monocytes, macrophages, etc. appear. This indicates that the cross-section specimens under the microscope show particularly severe viral pneumonia. In the HE-stained sections of the cross-section specimens of the patient with viral pneumonia, the serous cellulose exudate is concentrated to form a uniformly red-stained membrane on the alveolar cavity surface, namely the transparent membrane.

[0182] It can be seen that the HE-stained sections of the cross-sectional specimens prepared in the present invention, such as Figure 3 , 4 As shown, the image is clear and can perfectly display the lung tissue image of viral pneumonia.

[0183] In summary, the present invention provides a method for preparing a cross-sectional specimen based on the lungs of patients with viral pneumonia, which preserves precious clinical pathological data for subsequent research on viral pneumonia and avoids unnecessary infection of operators during the preparation process. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0184] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a lung cross-section specimen, in which a body is placed in a splash-proof autopsy isolation device in a biosafety autopsy room for processing, comprising the following steps: 1) The lungs are removed from the corpse by dissection, and the lungs are taken out after being immersed in a fixative to obtain a lung specimen; 2) using the elastic line method to position the horizontal cross-sectional reference line of the titanium dioxide dye on the surface of the lung specimen obtained in step 1), and then sawing the cutting line, and then freezing the lung specimen; 3) sawing the lung specimen frozen in step 2) along the sawing line, and verifying it by CT scanning to obtain a cross-sectional specimen; 4) Pathologically sampling, cleaning, gluing, imaging and sealing the cross-sectional specimens obtained in step 3); The corpse is placed in a splash-proof autopsy isolation device for processing, including the following steps: a) The splash-proof autopsy isolation device comprises a pollution source chamber and a semi-clean chamber separated by an isolation surface. The curtain door on the side of the pollution source chamber adjacent to the isolation surface is opened to place the corpse in the pollution source chamber. After closing the curtain door, the corpse is dissected and the lungs are removed through at least one first operation port provided on the other side adjacent to the isolation surface and / or at least one second operation port provided on the side opposite to the isolation surface. b) A second isolation curtain is provided on the side of the semi-clean chamber opposite to the isolation surface, and the lungs are transferred from the pollution source chamber to the semi-clean chamber through the first isolation curtain provided on the isolation surface through at least one third operation port provided on the second isolation curtain; c) placing the lung in a specimen storage container provided in a semi-clean chamber, soaking the lung in a fixative to obtain a lung specimen, then sawing the lung specimen, opening the second isolation curtain, taking out the lung specimen and freezing it; d) placing the frozen lung specimen into the semi-clean chamber through the second isolation curtain, sawing through the third operation port to obtain a cross-sectional specimen, and performing pathological sampling, cleaning, brushing glue and sealing on the cross-sectional specimen, and then taking it out through the second isolation curtain for imaging processing; e) The image-processed cross-sectional specimen is placed in a semi-clean chamber through a second isolation curtain to prepare a specimen box and then taken out.

2. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: The splash-proof autopsy isolation device includes adjacent pollution source chambers and semi-clean chambers, wherein the pollution source chambers are isolated from the semi-clean chambers by an isolation surface, and a first isolation curtain is provided on the isolation surface; on the pollution source chamber, a side surface adjacent to the isolation surface is a curtain door, and on the other side surface adjacent to the isolation surface is at least one first operating port, and on the side opposite to the isolation surface is at least one second operating port; on the semi-clean chamber, a second isolation curtain is provided on the side opposite to the isolation surface, and at least one third operating port is provided on the second isolation curtain.

3. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: Before the corpse is placed in the splash-proof autopsy isolation device, the hair of the corpse needs to be shaved, dirt and oil stains on the skin of the corpse need to be removed, and the corpse needs to be fixed with a bandage after being disinfected with a disinfectant; the disinfectant is an ethanol aqueous solution with a volume percentage of 70-80%.

4. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: In step 1), the lungs are immersed in a fixative solution by firstly injecting the fixative solution into the lungs through the opening of the tracheal stump, and then immersing the lungs filled with the fixative solution in the fixative solution; the fixative solution is a 5-15% neutral formalin solution; and the immersion time of the lungs in the fixative solution is 46-50 hours.

5. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: Step 2) includes any one or more of the following conditions: A1) the titanium dioxide is titanium dioxide; A2) the sawing line has a scribing depth of 1-2 cm; A3) The lung specimens must be sealed before freezing, and the freezing is to freeze the lung specimens at ≤-30°C for 4-6 days.

6. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: In step 3), the sawing is performed by a band saw, and the sawing loss of the band saw is less than 2 mm.

7. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: The pathological sampling comprises the following steps: A) Observe the pathological changes of the cross-section specimens at room temperature, and take the lesion tissue for examination if there are morphological changes; B) The sampled lesion tissues were sequentially subjected to gradient alcohol dehydration, xylene clearing, paraffin immersion, paraffin embedding, pathological tissue sectioning, slide attachment, tissue section xylene dewaxing, HE staining, gradient alcohol dehydration, xylene clearing, and gum sealing to obtain HE stained sections.

8. The method for preparing a lung cross-section specimen according to claim 1, characterized in that: The gelatin brushing method comprises brushing the surface of the section specimen with gelatin solution and then standing it to dry; the gelatin solution is obtained by hydrolyzing collagen, the concentration of the gelatin solution is 15-25%, and the number of times of brushing the gelatin solution is 1-3 times.

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