GB/T 21773: Evolution and historical versions
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Chemicals - Test method of in vivo mammalian erythrocyte micronucleus
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GB/T 21773-2025
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| GB/T 21773-2008 | English | 209 |
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Chemicals -- Test method of in vivo mammalian erythrocyte micronucleus
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GB/T 21773-2008
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Basic data | Standard ID | GB/T 21773-2025 (GB/T21773-2025) | | Description (Translated English) | Chemicals - Test method of in vivo mammalian erythrocyte micronucleus | | Sector / Industry | National Standard (Recommended) | | Date of Implementation | 2025-12-01 | | Older Standard (superseded by this standard) | GB/T 21773-2008 | GB/T 21773-2008: Chemicals -- Test method of in vivo mammalian erythrocyte micronucleus---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Chemicals.Test method of in vivo mammalian erythrocyte micronucleus
ICS 13.300; 11.100
A80
National Standards of People's Republic of China
Chemicals in vivo mammalian erythrocytes
Micronucleus test method
Posted.2008-05-12
2008-09-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
China National Standardization Administration released
Foreword
This standard is identical with the Organization for Economic Co-operation and Development (OECD) Guide to Testing Chemicals. 474 (1997) "In Vivo Mammals
Bone marrow polychromatic erythrocyte micronucleus test "(in English).
This standard made the following editorial changes.
--- Increased range of parts;
--- Unit of measurement into China's legal unit of measurement dosage;
--- Removed OECD references.
This standard by the National Standardization Technical Committee of hazardous chemicals management (SAC/TC251) and focal point.
This standard is drafted by. China Center for Disease Control Occupational Health and Poison Control.
Participated in the drafting of this standard. Tianjin Center for Disease Control and Prevention, Tianjin Inspection and Quarantine Science and Technology Research Institute.
The main drafters of this standard. Liu Keming, Hou Powder, Yang Deyi, Li Jin, Wang Chunhua, Yang Xueying, Zhang Yuan, Li Ningtao.
OECD Introduction
1. In vivo micronucleus test in mammals By analyzing polychromatic erythrocytes in rodent bone marrow and/or peripheral blood samples,
Detection of test-induced chromosome or red cell mitotic damage.
2. The purpose of the micronucleus test is to identify substances that can cause cytogenetic damage that can result in the presence of fragments or fragments
Chromosome micronucleus formation.
3. When the myeloid positive red blood cells evolve to polychromatic erythrocytes, their main nuclei are expelled, and the formed micronuclei then remain in the cell-free
Nuclear cytoplasm. It is easy to see because these cells lack the main nucleus. Occurrence of micronuclei in the poisoned animal polychromatic erythrocytes frequency
An increase in the rate is an indication of chromosomal damage.
4. Rodent bone marrow is routinely used in this assay because of the production of polychromatic erythrocytes in this tissue. If you have proof of some kind of animal
The spleen can not remove micronucleated erythrocytes or has been shown to be sufficiently sensitive to detect substances that cause chromosomal structure or number distortion
Sensory, then also consider the detection of its peripheral blood of nuclear immature (polychromatic) red blood cells. There are many criteria to judge micronucleus, among them
Including the presence or absence of centromeric or filamentous DNA in the micronucleus. The presence of immature (polychromatic) erythrocytes with micronuclei is the primary end
point. When the test animals were exposed continuously for 4 weeks or longer, some of the mature erythrocytes in the peripheral blood also contained micronuclei, at which time the mature
(Positive red) red blood cell count can also be used as the end of the trial.
5. Micronucleus test in mammals is particularly suitable for evaluating those who need to consider in vivo metabolism, pharmacokinetics and DNA repair
Mutagenicity hazards of various factors in the process. The above factors may differ between different animal species, different tissues and different genetic endpoints
with. Micronucleus test is also useful for further investigation of the mutagenicity that has been detected in in vitro systems.
6. If there is evidence that the test substance or active metabolites can not reach the appropriate target tissue, then this test is not suitable for use.
Chemicals in vivo mammalian erythrocytes
Micronucleus test method
1 Scope
This standard specifies the scope of the mammalian erythrocyte micronucleus test, terms and definitions, the basic principles of the test, test methods, the number of tests
According to and report.
This standard applies to the detection of mutagenic chemicals.
2 Terms and definitions
The following terms and definitions apply to this standard.
2.1
In the cell division, the chromosomes are associated with spindle filaments so that the daughter chromosomes move in an orderly manner toward the poles of the daughter cell.
2.2
At the end of mitosis (meiosis), cells that are produced by fragments of the backward chromosome or the entire chromosome, isolated or attached to the main nucleus of the cell
Small nucleus.
2.3
Mature red blood cells, due to the lack of ribosomes, can be distinguished by selective ribosomal dyes from immature polychromatic erythrocytes.
2.4
Immature red blood cells, in the developmental period, still contains ribosomes, it can be used to distinguish between selective ribosomal dye and mature positive red blood cells
Come on.
3 test the basic principles
The animals to be tested are exposed to the appropriate routes of exposure. If a bone marrow sample is used, the animal is sacrificed at the appropriate time after exposure to extract the bone
Pith, filming and dyeing. When using a peripheral blood sample, blood is drawn, smeared and stained at the appropriate time after exposure, and the last dose and
The time between cell harvests should be as short as possible. Analyze the micronucleus present in the tablets.
4 test methods
4.1 Preparation
4.1.1 Animal species selection
If bone marrow samples are used, mice and rats are recommended, although other suitable mammals may also be used. When using a peripheral blood sample,
It is recommended to use mice. However, if the spleen of an animal does not clear the micronucleated erythrocytes, or it has been shown that some animal can detect
Such animals can be used with sufficient sensitivity to chromosomal structures or numbers of aberrations. The animal used for the general test should be the beginning
Adult healthy animals. At the beginning of the experiment, the difference in body weight of the animal is small, and the same sex can not exceed ± 20% of the average body weight.
4.1.2 feeding conditions
The temperature in the animal room should be 22 ℃ ± 3 ℃, the relative humidity should not exceed 70% and the target should be 50% ~ 60%
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