Test No. 474: Mammalian Erythrocyte Micronucleus Test
2014; Organization for Economic Cooperation and Development; Linguagem: Inglês
10.1787/9789264224292-en
Tópico(s)Cancer-related Molecular Pathways
Resumo© OECD, (2016)immature erythrocytes in treated animals is an indication of induced structural or numerical chromosomal aberrations. 6.Newly formed micronucleated erythrocytes are identified and quantitated by staining followed by either visual scoring using a microscope, or by automated analysis.Counting sufficient immature erythrocytes in the peripheral blood or bone marrow of adult animals is greatly facilitated by using an automated scoring platform.Such platforms are acceptable alternatives to manual evaluation (2).Comparative studies have shown that such methods, using appropriate calibration standards, can provide better inter-and intra-laboratory reproducibility and sensitivity than manual microscopic scoring (3) (4).Automated systems that can measure micronucleated erythrocyte frequencies include, but are not limited to, flow cytometers ( 5), image analysis platforms (6) (7), and laser scanning cytometers (8). 7.Although not normally done as part of the test, chromosome fragments can be distinguished from whole chromosomes by a number of criteria.These include identification of the presence or absence of a kinetochore or centromeric DNA, both of which are characteristic of intact chromosomes.The absence of kinetochore or centromeric DNA indicates that the micronucleus contains only fragments of chromosomes, while the presence is indicative of chromosome loss. 8.Definitions of terminology used are set out in Annex 1.
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