Piece preparation method of peripheral blood chromosome

Abstract

The invention provides a preparation method of peripheral blood chromosomes. The preparation method comprises the following steps: inoculation and cell culture: inoculating fresh peripheral blood whole blood into a cell culture medium, and culturing for 68-72 hours; adding colchicine into the culture medium before culture is ended, uniformly mixing, and culturing; taking out the culture medium, performing centrifugal treatment, and removing supernate; adding a hypotonic solution into the centrifugal tube, blowing and beating, and then carrying out constant-temperature water bath treatment; sequentially carrying out pre-fixing, fixing and re-fixing and putting into a refrigerator for storage; taking out the reserve substance, centrifuging, and discarding the supernatant; adding a stationary liquid, and blowing and beating into a cell suspension; then taking out the clean frozen slide, and dropwise adding the cell suspension on the slide; wiping the back surface of the slide, burning with outer flame of an alcohol lamp, and then drying; digesting the slide, immediately rinsing the slide in normal saline, and dyeing the slide in a dye vat for 5-10 minutes; and washing with running water, and drying to obtain the chromosome specimen. The chromosome prepared by using the paper cup has more split phases, longer chromosomes and better dispersity.

Description

Technical Field

[0001] The invention belongs to the technical field of medical testing, and specifically relates to a method for preparing peripheral blood chromosomes. Background Art

[0002] Chromosomes are linear or circular structures composed of DNA and proteins in the cell nucleus, which are responsible for carrying and transmitting genetic information. Chromosomes condense highly during cell division, forming visible rod-shaped or X-shaped structures, which are easy to observe under a microscope. Chromosomes are one of the core objects of genetic research and are of great significance for understanding the genetic characteristics, developmental processes and disease mechanisms of organisms.

[0003] The preparation of peripheral blood chromosomes mainly includes the steps of culture, harvesting, hypotonicity, fixation, banding, staining and slide preparation. The process of peripheral blood chromosome preparation is complicated, and often results in small analyzable division figures, short and thick chromosomes, and poor dispersion, which reduces the success rate of chromosome karyotype analysis and its clinical practicality. Conventional chromosome analysis is difficult to detect abnormalities of <10M bases. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing peripheral blood chromosomes, by rationally processing samples, optimizing cell culture medium and culture conditions, obtaining high-quality chromosome preparations, and providing a reliable basis for clinical diagnosis and scientific research.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing peripheral blood chromosomes comprises the following steps: S1: Inoculation and cell culture: Take 0.8-1ml of fresh peripheral blood and inoculate it into the cell culture medium, shake it well and culture it in a 37℃ constant temperature incubator for 68-72h; S2: Colchicine treatment: before terminating the culture, add 0.01-0.0.2 ml of 20 μg / ml colchicine to the culture medium in step S1, mix well, and culture in a 37°C constant temperature incubator for 1.5-2.5 h; S3: Hypotonic treatment: Take out the culture medium obtained in step S2, put it into a centrifuge tube for centrifugation, and remove the supernatant; then add hypotonic solution to the centrifuge tube to make it 6-10 ml, blow vigorously, and keep it in a constant temperature 37°C water bath for 25-45 minutes; S4: Fixative treatment: add 0.5-1.5 ml of fixative to the centrifuge tube treated in step S3 for pre-fixation, mix, centrifuge, and discard the supernatant; then add 6-10 ml of fixative to the centrifuge tube for fixation, mix, stand at room temperature, centrifuge, and discard the supernatant; then add 3-7 ml of fixative to the centrifuge tube for re-fixation, mix, and put in the refrigerator for storage; S5: Preparation: Take out the stored material in step S4, centrifuge and discard the supernatant; then add the fixative and blow to form a cell suspension; then take out the clean frozen glass slide and drop the cell suspension on the glass slide; wipe the back of the glass slide dry, burn it with the outer flame of an alcohol lamp, and then dry it; S6: Staining: Digest the slide for 36-40 seconds, and immediately rinse it in physiological saline to fully terminate the digestion; then place the slide in a staining tank and stain it for 5-10 minutes; rinse it with running water and dry it to obtain the chromosome specimen.

[0006] Furthermore, the culture medium in step S1 is: 15-25mmol / L RPMI 1640, 10-15mmol / L ATP, 25-35mmol 4-hydroxyethylpiperazineethanesulfonic acid, 3-6mmol cysteine ​​hydrochloride, 2-5mmol penicillin, 1-3mmol fetal bovine serum, and 0.2mg / ml CDKl / CyclinB.

[0007] Furthermore, in step S3, the hypotonic solution is 0.05-0.08 mol / L sodium chloride or 0.8-1.3 mol / L propylene glycol.

[0008] Furthermore, the rotation speed of the centrifugal treatment in step S3 is 1600-2000 rpm, and the time is 4-6 min.

[0009] Furthermore, in step S3, the mixture is blown vigorously 30-40 times with a disposable pipette.

[0010] Furthermore, step S4 is specifically as follows: add 0.5-1.5 ml of fixative solution to the centrifuge tube processed in step S3 for pre-fixation, mix well, centrifuge at a speed of 1600-2000 rpm for 4-6 min, and discard the supernatant; then add 6-10 ml of fixative solution to the centrifuge tube for fixation, mix well, let stand at room temperature for 25-35 min, centrifuge at a speed of 1600-2000 rpm for 4-6 min, and discard the supernatant; then add 3-7 ml of fixative solution to the centrifuge tube for re-fixation, mix well, and put in the refrigerator for storage.

[0011] Furthermore, in step S4, the fixing liquid is prepared by methanol and glacial acetic acid in a volume ratio of 2.5-3.5:1.

[0012] Furthermore, in step S5, the reserve material in step S4 is taken out, centrifuged at a speed of 1600-2000 rpm for 4-6 minutes, and the supernatant is discarded; then 0.4-0.8 ml of fixative is added, and the cell suspension is formed by gently pipetting for 6-10 times with a disposable pipette.

[0013] Furthermore, in step S5, the clean frozen glass slide is then taken out, and 1-3 drops of cell suspension are added to the glass slide; the back of the glass slide is wiped dry, and the outer flame of an alcohol lamp is used for 2-4 times, each time for 1-3 seconds, and then placed in a drying oven at 90°C for 30 minutes or at 75°C for 3 hours.

[0014] Furthermore, step S6 is specifically as follows: put 3 glass jars in a 37°C water bath, add 48ml of normal saline, 2ml of 0.5% trypsin and 8 drops of 3% Tris solution into the first jar, mix well, add 50ml of normal saline into the second jar, add 45ml of steamed stuffing water, 5ml of Giemsa stain and 8 drops of 3% Tris solution into the third jar, mix well and pre-warm; digest the slide for 36-40 seconds, immediately put it into the second jar of normal saline and rinse it once to fully terminate the digestion; then put the slide into the stain jar and stain it for 5-10 minutes, rinse it with running water, dry it at room temperature or bake it dry before reading the slide.

[0015] Compared with the prior art, the advantages and beneficial effects of the present invention are: The invention obtains peripheral blood chromosome specimens through the processes of inoculation and cell culture, colchicine treatment, hypotonic treatment, fixation treatment, slice preparation, staining and the like in sequence; by selecting culture medium, hypotonic solution, fixative solution, staining solution and the like, the process parameters of each process are optimized, and compared with conventional peripheral blood chromosome slice preparation, the specimens have more mitotic phases, longer chromosomes and better dispersion; the detection rate of small abnormal chromosomes is higher, and the success rate of chromosome analysis is higher. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0017] The raw materials used in the present invention are: RPMI 1640 (Shanghai Youningwei Biotechnology Co., Ltd., C22400500BT); ATP (Hunan Huibaiyi New Materials Co., Ltd., HBY0129); penicillin (Hubei Weideli Chemical Reagent Co., Ltd., HBWS-2059); cysteine ​​hydrochloride (Leshengyuan Biotechnology (Nanjing) Co., Ltd., S-02); fetal bovine serum (Guangzhou Yining Biotechnology Co., Ltd., ST30-3302); cyclin-dependent kinase 1 / cyclin B (Invitrogen); colchicine (Shanghai Xuanke Biotechnology Co., Ltd., XK0192); pancreatin (Shanghai Yuanye Biotechnology Co., Ltd., S10031); Tris solution (Huizhiheyuan Biotechnology (Suzhou) Co., Ltd., 011700.05); Giemsa stain (Shanghai Yuanye Biotechnology Co., Ltd., S19006).

[0018] Example 1 A method for preparing peripheral blood chromosomes comprises the following steps: S1: Inoculation and cell culture: Take fresh blood within 72 hours next to the flame of an alcohol lamp, insert the injection needle directly through the sample hole of the culture medium, inject 0.8 ml of whole blood into the culture medium, shake it gently and place it in a 37°C constant temperature incubator for culture; the composition of the culture medium is: 15 mmol / L RPMI 1640, 10 mmol / L ATP, 25 mmol 4-hydroxyethylpiperazineethanesulfonic acid, 3 mmol cysteine ​​hydrochloride, 2 mmol penicillin, 1 mmol fetal bovine serum, 0.2 mg / ml CDKl / CyclinB (cyclin-dependent kinase 1 / cyclin B); Place the culture medium flat (at about 15°, so that the culture medium does not touch the lid) and culture for 1 h. The ambient temperature for peripheral blood lymphocyte culture is 37°C ± 0.5°C, and must be based on the internal temperature of the incubator. S2: Colchicine treatment: before terminating the culture, add 0.01 ml of colchicine at a concentration of 20 ug / ml to the culture medium (use a 2 ml syringe with a No. 6 needle to vertically add 2 drops) to make the final concentration 0.04 ug / ml, mix gently, and culture in a 37°C constant temperature incubator for 1.5 h; S3: Hypotonic treatment: After colchicine treatment, take the culture medium out of the incubator and centrifuge it in a horizontal centrifuge (1800 rpm, 5 min). Carefully remove the supernatant, add pre-warmed 37°C hypotonic solution to the centrifuge tube to 6 mL, pipette vigorously for 30 times, and place in a 37°C constant temperature water bath for 25 min. The hypotonic solution is 0.05 mol / L sodium chloride. S4: Fixative treatment: add 0.5 ml of fixative to the centrifuge tube treated in step S3 for pre-fixation, mix well, centrifuge at 1600 rpm for 4 min, and discard the supernatant; then add 6 ml of fixative to the centrifuge tube for fixation, mix well, let stand at room temperature for 25 min, centrifuge at 1600 rpm for 4 min, and discard the supernatant; then add 3 ml of fixative to the centrifuge tube for re-fixation, mix well, and put in a refrigerator for storage; the fixative is prepared by methanol and glacial acetic acid in a volume ratio of 2.5:1; S5: Preparation: Take out the prepared material in step S4, centrifuge at 1600 rpm for 4 min, and discard the supernatant; then add 0.4 ml of fixative, and gently blow 6 times with a disposable pipette to form a cell suspension; then take out a clean frozen glass slide, and drop 1 drop of cell suspension on the glass slide; wipe the back of the glass slide dry, burn it twice with the outer flame of an alcohol lamp, each time for 3 seconds, and then place it in a 90°C drying oven to dry for 30 minutes; S6: Staining: Put 3 glass jars in a 37°C water bath, add 48ml of normal saline, 2ml of 0.5% trypsin and 8 drops of 3% Tris solution into the first jar, mix well, add 50ml of normal saline into the second jar, add 45ml of steamed stuffing water, 5ml of Giemsa stain and 8 drops of 3% Tris solution into the third jar, mix well and pre-warm; digest the slides for 36-40 seconds, immediately rinse them in the second jar of normal saline to fully terminate the digestion; then clamp the slides into the staining jar and stain for 1 minute, rinse them with running water, dry them at room temperature or bake them dry before reading the slides.

[0019] Observing the banding and staining effects under the microscope, the chromosomes are longer, with clearer shapes, clearer bands, and better dispersion.

[0020] Example 2 A method for preparing peripheral blood chromosomes comprises the following steps: S1: Inoculation and cell culture: Take fresh blood within 72 hours next to the flame of an alcohol lamp, insert the injection needle directly through the sample hole of the culture medium, inject 1 ml of whole blood into the culture medium, shake it gently and place it in a 37°C constant temperature incubator for culture; the composition of the culture medium is: 25mmol / L RPMI 1640, 15mmol / L ATP, 35mmol 4-hydroxyethylpiperazineethanesulfonic acid, 6mmol cysteine ​​hydrochloride, 5mmol penicillin, 3mmol fetal bovine serum, 0.2mg / ml CDK1 / CyclinB; Place the culture medium flat (at about 15°, so that the culture medium does not touch the lid) and culture for 72 hours; the ambient temperature for peripheral blood lymphocyte culture is 37°C ± 0.5°C, and must be based on the internal temperature of the incubator; S2: Colchicine treatment: before terminating the culture, add 0.02 ml of colchicine at a concentration of 20 ug / ml to the culture medium (use a 2 ml syringe with a No. 6 needle to vertically add 3 drops) to make the final concentration 0.08 ug / ml, mix gently, and culture in a 37°C constant temperature incubator for 2.5 h; S3: Hypotonic treatment: After colchicine treatment, take the culture medium out of the incubator and centrifuge it in a horizontal centrifuge (1800 rpm, 5 min). Carefully remove the supernatant, add pre-warmed 37°C hypotonic solution to the centrifuge tube to 10 mL, pipette vigorously for 40 times with a disposable pipette, and place in a 37°C constant temperature water bath for 45 min. The hypotonic solution is 0.08 mol / L sodium chloride. S4: Fixative treatment: add 1.5 ml of fixative to the centrifuge tube treated in step S3 for pre-fixation, mix well, centrifuge at 2000 rpm for 6 min, and discard the supernatant; then add 10 ml of fixative to the centrifuge tube for fixation, mix well, let stand at room temperature for 35 min, centrifuge at 2000 rpm for 6 min, and discard the supernatant; then add 7 ml of fixative to the centrifuge tube for re-fixation, mix well, and put in a refrigerator for storage; the fixative is prepared by methanol and glacial acetic acid in a volume ratio of 3.5:1; S5: Preparation: Take out the prepared material in step S4, centrifuge at 2000 rpm for 6 min, and discard the supernatant; then add 0.8 ml of fixative and gently blow 10 times with a disposable pipette to form a cell suspension; then take out a clean frozen glass slide and drop 3 drops of cell suspension on the glass slide; wipe the back of the glass slide dry, burn it with an alcohol lamp for 4 times, each time for 3 seconds, and then place it in a 90°C drying oven to dry for 30 minutes; S6: Staining: Put 3 glass jars in a 37°C water bath, add 48ml of normal saline, 2ml of 0.5% trypsin and 8 drops of 3% Tris solution into the first jar, mix well, add 50ml of normal saline into the second jar, add 45ml of steamed stuffing water, 5ml of Giemsa stain and 8 drops of 3% Tris solution into the third jar, mix well and pre-warm; digest the slides for 36-40 seconds, immediately rinse them in the second jar of normal saline to fully terminate the digestion; then clamp the slides into the staining jar and stain for 5 minutes, rinse them with running water, dry them at room temperature or bake them dry before reading the slides.

[0021] Observing the banding and staining effects under the microscope, the chromosomes are longer, with clearer shapes, clearer bands, and better dispersion.

[0022] Example 3 A method for preparing peripheral blood chromosomes comprises the following steps: S1: Inoculation and cell culture: Take fresh blood within 72 hours next to the flame of an alcohol lamp, insert the injection needle directly through the sample hole of the culture medium, inject 0.9 ml of whole blood into the culture medium, shake it gently and place it in a 37°C constant temperature incubator for culture; the composition of the culture medium is: 22 mmol / L RPMI 1640, 13 mmol / L ATP, 32 mmol 4-hydroxyethylpiperazineethanesulfonic acid, 5 mmol cysteine ​​hydrochloride, 3 mmol penicillin, 2 mmol fetal bovine serum, 0.2 mg / ml CDKl / CyclinB; Place the culture medium flat (at about 15°, so that the culture medium does not touch the lid) and culture for 70 hours; the ambient temperature for peripheral blood lymphocyte culture is 37°C ± 0.5°C, and must be based on the internal temperature of the incubator; S2: Colchicine treatment: before terminating the culture, add 0.015 ml of colchicine at a concentration of 20 ug / ml to the culture medium (use a 2 ml syringe with a No. 6 needle to vertically add 2-3 drops) to make the final concentration 0.06 ug / ml, mix gently, and culture in a 37°C constant temperature incubator for 2 hours; S3: Hypotonic treatment: After colchicine treatment, take the culture medium out of the incubator and centrifuge it in a horizontal centrifuge (1800 rpm, 5 min). Carefully remove the supernatant, add 8 mL of pre-warmed 37°C hypotonic solution to the centrifuge tube, pipette vigorously for 35 times, and place in a 37°C constant temperature water bath for 40 min. The hypotonic solution is 0.07 mol / L sodium chloride or 1 mol / L propylene glycol. S4: Fixative treatment: add 0.8 ml of fixative to the centrifuge tube treated in step S3 for pre-fixation, mix well, centrifuge at 1800 rpm for 5 min, and discard the supernatant; then add 8 ml of fixative to the centrifuge tube for fixation, mix well, let stand at room temperature for 30 min, centrifuge at 1800 rpm for 5 min, and discard the supernatant; then add 5 ml of fixative to the centrifuge tube for re-fixation, mix well, and put in the refrigerator for storage; the fixative is prepared by methanol and glacial acetic acid in a volume ratio of 3:1; S5: Preparation: Take out the prepared material in step S4, centrifuge at 1800 rpm for 5 min, and discard the supernatant; then add 0.6 ml of fixative, and gently blow 8 times with a disposable pipette to form a cell suspension; then take out a clean frozen glass slide, and drop 2 drops of cell suspension on the glass slide; wipe the back of the glass slide dry, burn it with an alcohol lamp for 3 times, each time for 2 seconds, and then place it in a 90°C drying oven to dry for 30 minutes; S6: Staining: Place 3 glass jars in a 37°C water bath, add 48ml of saline, 2ml of 0.5% trypsin and 8 drops of 3% Tris solution into the first jar, mix well, add 50ml of saline into the second jar, add 45ml of steamed stuffing water, 5ml of Giemsa stain and 8 drops of 3% Tris solution into the third jar, mix well and pre-warm; digest the slides for 38 seconds, immediately rinse them in the second jar of saline to fully terminate the digestion; then clamp the slides into the staining jar and stain for 2 minutes, rinse them with running water, dry them at room temperature or bake them dry before reading the slides.

[0023] The banding and staining effects were observed under the microscope. The chromosomes were long, with clear morphology, distinct bands and good dispersion.

[0024] Comparative Example 1 The difference from Example 1 is that the composition of the culture medium in step S1 is: 15mmol / L RPMI 1640, 2mmol penicillin, 25μmol, 1mmol fetal bovine serum, 0.2mg / ml CDK1 / Cyclin B, and the other steps remain unchanged. The banding and staining effects were observed under a microscope, and the chromosomes were small, the edges were rough, the dispersion was poor, and the banding was fuzzy.

[0025] Comparative Example 2 The difference from Example 1 is that the concentration of colchicine in step S2 is 40 ug / ml, and the other steps remain unchanged. The banding and staining effects were observed under a microscope, and the chromosomes were short, with rough edges, poor dispersion, and blurred bands.

[0026] Comparative Example 3 The difference from Example 1 is that in step S3, the disposable pipette is used to blow vigorously for 10 times, and the other steps remain unchanged. The banding and staining effects were observed under a microscope, and the chromosomes were small, with rough edges, poor dispersion, and fuzzy banding.

[0027] Comparative Example 4 The difference from Example 1 is that the fixing solution in step S4 is prepared by methanol and glacial acetic acid in a volume ratio of 5:1, and the other steps remain unchanged. The banding and staining effects were observed under a microscope, and the chromosomes were short, with rough edges, poor dispersion, and fuzzy bands.

[0028] From the above results, it can be seen that the chromosome preparations prepared in Examples 1-3 are better. In particular, the comprehensive performance of Example 3 is the most outstanding. However, since Comparative Examples 1-4 do not adopt the necessary technical solutions, their corresponding performance tests are obviously worse than those of the Examples. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0029] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing peripheral blood chromosomes, characterized in that: The steps include: S1: Inoculation and cell culture: Take 0.8-1ml of fresh peripheral blood and inoculate it into the cell culture medium, shake it well and culture it in a 37℃ constant temperature incubator for 68-72h; S2: Colchicine treatment: before terminating the culture, add 0.01-0.0.2 ml of 20 μg / ml colchicine to the culture medium in step S1, mix well, and culture in a 37°C constant temperature incubator for 1.5-2.5 h; S3: Hypotonic treatment: Take out the culture medium obtained in step S2, put it into a centrifuge tube for centrifugation, and remove the supernatant; then add hypotonic solution to the centrifuge tube to make it 6-10 ml, blow vigorously, and keep it in a constant temperature 37°C water bath for 25-45 minutes; S4: Fixative treatment: add 0.5-1.5 ml of fixative to the centrifuge tube treated in step S3 for pre-fixation, mix, centrifuge, and discard the supernatant; then add 6-10 ml of fixative to the centrifuge tube for fixation, mix, stand at room temperature, centrifuge, and discard the supernatant; then add 3-7 ml of fixative to the centrifuge tube for re-fixation, mix, and put in the refrigerator for storage; S5: Preparation: Take out the stored material in step S4, centrifuge and discard the supernatant; then add the fixative and blow to form a cell suspension; then take out the clean frozen glass slide and drop the cell suspension on the glass slide; wipe the back of the glass slide dry, burn it with the outer flame of an alcohol lamp, and then dry it; S6: Staining: Digest the slide for 36-40 seconds, and immediately rinse it in physiological saline to fully terminate the digestion; then place the slide in a staining tank and stain it for 5-10 minutes; rinse it with running water and dry it to obtain the chromosome specimen.

2. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: The culture medium in step S1 is: 15-25mmol / L RPMI 1640, 10-15mmol / L ATP, 25-35mmol 4-hydroxyethylpiperazineethanesulfonic acid, 3-6mmol cysteine ​​hydrochloride, 2-5mmol penicillin, 1-3mmol fetal bovine serum, and 0.2mg / ml CDK1 / CyclinB.

3. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: In step S3, the hypotonic solution is 0.05-0.08 mol / L sodium chloride or 0.8-1.3 mol / L propylene glycol.

4. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: The rotation speed of the centrifugal treatment in step S3 is 1600-2000 rpm, and the time is 4-6 min.

5. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: In step S3, pipette vigorously for 30-40 times with a disposable pipette.

6. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: Step S4 is specifically as follows: add 0.5-1.5 ml of fixative solution to the centrifuge tube processed in step S3 for pre-fixation, mix well, centrifuge at a speed of 1600-2000 rpm for 4-6 min, and discard the supernatant; then add 6-10 ml of fixative solution to the centrifuge tube for fixation, mix well, let stand at room temperature for 25-35 min, centrifuge at a speed of 1600-2000 rpm for 4-6 min, and discard the supernatant; then add 3-7 ml of fixative solution to the centrifuge tube for re-fixation, mix well, and put in the refrigerator for storage.

7. The method for preparing peripheral blood chromosomes according to claim 6, characterized in that: In step S4, the fixing liquid is prepared by mixing methanol and glacial acetic acid in a volume ratio of 2.5-3.5:

1.

8. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: In step S5, the stored material in step S4 is taken out, centrifuged at 1600-2000 rpm for 4-6 min, and the supernatant is discarded; then 0.4-0.8 ml of fixative is added, and the cell suspension is formed by gently pipetting for 6-10 times with a disposable pipette.

9. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: As described in step S5, the clean frozen glass slide is then taken out, and 1-3 drops of cell suspension are added to the glass slide; the back of the glass slide is wiped dry, and the outer flame of an alcohol lamp is used to burn it 2-4 times, each time for 1-3 seconds, and then placed in a drying oven at 90°C for 30 minutes or at 75°C for 3 hours.

10. The method for preparing peripheral blood chromosomes according to claim 1, characterized in that: Step S6 is specifically as follows: put three glass jars in a 37°C water bath, add 48ml of normal saline, 2ml of 0.5% trypsin and 8 drops of 3% Tris solution into the first jar, mix well, add 50ml of normal saline into the second jar, add 45ml of steamed stuffing water, 5ml of Giemsa stain and 8 drops of 3% Tris solution into the third jar, mix well and pre-warm; digest the slide for 36-40 seconds, immediately put it into the second jar of normal saline and rinse it once to fully terminate the digestion; then put the slide into the stain jar and stain it for 5-10 minutes, rinse it with running water, dry it at room temperature or bake it dry before reading the slide.