Latest Documents


  • 27-March-2017

    English

    Good Laboratory Practice (GLP)

    The OECD Principles of Good Laboratory Practice (GLP) ensure the generation of high quality and reliable test data related to the safety of industrial chemical substances and preparations. The principles have been created in the context of harmonising testing procedures for the Mutual Acceptance of Data (MAD).

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  • 27-March-2017

    English

    OECD Good Laboratory Practice: Frequently asked questions (FAQ)

    GLP issues raised by testing labs are covered in this comprehensive list of questions and answers, recently updated with questions related to Validation of Software Programmes which Support OECD Test Guidelines

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  • 18-October-2016

    English

    Developmental neurotoxicity: OECD/EFSA experts discuss non-animal test methods

    Participants from 15 countries attended the Workshop on Developmental Neurotoxicity: The use of non-animal test methods for regulatory purposes” on 18 October 2016, in Belgium. The event, co-organised by the OECD and the European Food Safety Authority (EFSA), focused on opportunities and challenges related to alternative methods for testing and assessing the DNT potential of chemicals.

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  • 20-September-2016

    English

    OECD publishes new and updated Test Guidelines for effects on human health and on environmental species

    The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. Every year new and updated Test Guidelines are adopted to meet the regulatory needs in OECD member countries. The most recent Test Guidelines were adopted in July 2016.

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  • 29-July-2016

    English

    Test No. 473: In Vitro Mammalian Chromosomal Aberration Test

    The purpose of the in vitro chromosome aberration test is to identify agents that cause structural chromosome aberrations in cultured mammalian somatic cells. Structural aberrations may be of two types: chromosome or chromatid.

    The in vitro chromosome aberration test may employ cultures of established cell lines, cell strains or primary cell cultures. Cell cultures are exposed to the test substance (liquid or solid) both with and without metabolic activation during about 1.5 normal cell cycle lengths. At least three analysable concentrations of the test substance should be used. At each concentration duplicate cultures should normally be used. At predetermined intervals after exposure of cell cultures to the test substance, the cells are treated with a metaphase-arresting substance, harvested, stained. Metaphase cells are analysed microscopically for the presence of chromosome aberrations.

  • 29-July-2016

    English

    Test No. 476: In Vitro Mammalian Cell Gene Mutation Tests using the Hprt and xprt genes

    The in vitro mammalian cell gene mutation test can be used to detect gene mutations induced by chemical substances. In this test, the used genetic endpoints measure mutation at hypoxanthine-guanine phosphoribosyl transferase (HPRT), and at a transgene of xanthineguanine phosphoribosyl transferase (XPRT). The HPRT and XPRT mutation tests detect different spectra of genetic events.

    Cells in suspension or monolayer culture are exposed to, at least four analysable concentrations of the test substance, both with and without metabolic activation, for a suitable period of time. They are subcultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is usually determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each selected locus and cell type, to allow near-optimal phenotypic expression of induced mutations. Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted.

  • 29-July-2016

    English

    Test No. 487: In Vitro Mammalian Cell Micronucleus Test

    The in vitro micronucleus test is a genotoxicity test for the detection of micronuclei in the cytoplasm of interphase cells. Micronuclei may originate from acentric chromosome fragments (i.e. lacking a centromere), or whole chromosomes that are unable to migrate to the poles during the anaphase stage of cell division. The assay detects the activity of clastogenic and aneugenic test substances in cells that have undergone cell division during or after exposure to the test substance. This Test Guideline allows the use of protocols with and without the actin polymerisation inhibitor cytochalasin B. Cytochalasin B allows for the identification and selective analysis of micronucleus frequency in cells that have completed one mitosis, because such cells are binucleate. This Test Guideline also allows the use of protocols without cytokinesis block provided there is evidence that the cell population analysed has undergone mitosis.

  • 29-July-2016

    English

    Test No. 475: Mammalian Bone Marrow Chromosomal Aberration Test

    The mammalian in vivo chromosome aberration test is used for the detection of structural chromosome aberrations induced by test compounds in bone marrow cells of animals, usually rodents (rats, mice and Chinese hamsters). Structural chromosome aberrations may be of two types: chromosome or chromatid.

    Animals are exposed to the test substance (liquid or solid) by an appropriate route of exposure (usually by gavage using a stomach tube or a suitable intubation cannula, or by intraperitoneal injection) and are sacrificed at appropriate times after treatment. Prior to sacrifice, animals are treated with a metaphase-arresting agent. Chromosome preparations are then made from the bone marrow cells and stained, and metaphase cells are analysed for chromosome aberrations. Each treated and control group must include at least 5 analysable animals per sex. The limit dose is 2000 mg/kg/body weight/day for treatment up to 14 days, and 1000 mg/kg/body weight/day for treatment longer than 14 days.

  • 29-July-2016

    English

    Test No. 490: In Vitro Mammalian Cell Gene Mutation Tests Using the Thymidine Kinase Gene

    The in vitro mammalian cell gene mutation test can be used to detect gene mutations induced by chemical substances. This TG includes two distinct in vitro mammalian gene mutation assays requiring two specific tk heterozygous cells lines: L5178Y tk+/-3.7.2C cells for the mouse lymphoma assay (MLA) and TK6 tk+/- cells for the TK6 assay. Genetic events detected using the tk locus include both gene mutations and chromosomal events.

    Cells in suspension or monolayer culture are exposed to, at least four analysable concentrations of the test substance, both with and without metabolic activation, for a suitable period of time. They are subcultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is usually determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each selected locus and cell type, to allow near-optimal phenotypic expression of induced mutations. Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted.

  • 29-July-2016

    English

    Test No. 489: In Vivo Mammalian Alkaline Comet Assay

    The in vivo alkaline single cell gel electrophoresis assay, also called alkaline Comet Assay is a method measuring DNA strand breaks in eukaryotic cells.

    Each treated group is composed of a minimum of 5 animals of one sex (or of each sex as appropriate). A positive and a vehicle control group are also used. Administration of the treatment consists of daily doses over duration of 2 days or more, ensuring the test chemical reaches the target tissue which can be the liver, the kidney or other tissues if justified.

    Tissues of interest are dissected and single cells/nuclei suspensions are prepared and embedded in agarose on slides. Cells/nuclei are treated with lysis buffer to remove cellular and/or nuclear membranes. The nuclear DNA in the agar is then subjected to electrophoresis at high pH. This results in structures resembling comets which by using suitable fluorescent stain, can be observed by fluorescent microscopy. Based on their size DNA fragments migrate away from the head to the tail, and the intensity of the comet tail relative to the total intensity (head plus tail) reflects the amount of DNA breakage.

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