The Organisation for Economic Co-operation and Development (OECD) is an intergovernmental organisation in which representatives of 36 industrialised countries in North and South America, Europe and the Asia and Pacific region, as well as the European Commission, meet to co-ordinate and harmonise policies, discuss issues of mutual concern, and work together to respond to international problems. Most of the OECD’s work is carried out by more than 200 specialised committees and working groups composed of member country delegates. Observers from several countries with special status at the OECD, and from interested international organisations, attend many of the OECD’s workshops and other meetings. Committees and working groups are served by the OECD Secretariat, located in Paris, France, which is organised into directorates and divisions.

A guidance document on Good In Vitro Method Practices (GIVIMP) for the development and implementation of in vitro methods for regulatory use in human safety assessment was identified as a high priority requirement by the OECD. The aim of this guidance document is to reduce the uncertainties in cell and tissue-based in vitro method derived predictions by applying all necessary good scientific, technical and quality practices from in vitro method development to in vitro method implementation for regulatory use. This guidance document also applies to in vitro methods already accepted by the OECD.

There is a scientific policy and regulatory desire for validated and internationally accepted in vitro methods (e.g., OECD test guidelines or ISO standards). To accommodate the needs of receiving authorities, a number of in vitro methods, often based on the use of human cells and tissues, have been submitted to international validation bodies during the last two decennia. It was agreed that technical guidance is needed to standardise and advance the development of robust and reliable in vitro methods suitable for regulatory purposes. The OECD approached EURL ECVAM to coordinate the drafting of GIVIMP for the development and implementation of in vitro methods for regulatory use in human safety assessment which is also equally applicable to non-guideline or not internationally recognised in vitro methods.

The rapid expansion in in vitro methods, along with improved understanding of the biological processes involved in toxicological sequelae, have facilitated the development of a variety of predictive in vitro methods. These in vitro methods can be robust alternatives to using animals to identify and characterise chemical safety hazards. In some regulatory sectors, recent changes in regulation now accept, or in some cases, require, in vitro data in lieu of data from animal studies. When the scientific suitability has been demonstrated, the use of in vitro methods can reduce the resources required and increase the efficacy of chemical safety evaluation. In order for these alternatives to be used in regulatory decision making the scientific integrity and quality assurance must be assured.

The major goal of GIVIMP consists of improving the reliability and robustness of in vitro methods, reducing the uncertainties of in vitro based predictions and therefore increasing the acceptance of the in vitro estimated safety measures by regulatory agencies. The scope of the GIVIMP guidance, taking into account good scientific, technical and quality practices, is to ensure that the overall process, starting from in vitro method development to the final in vitro method implementation for regulatory use is more efficient and effective.

Key message: The in vitro method life cycle from development to their use for safety assessment purposes has a variety of key actors and the guidance identifies clearly their responsibilities, both individually and collectively.Key content: Describes all target groups involved in the process e.g., in vitro method developers, test system (cells, tissues) providers, validation bodies, inter-governmental organisations for cooperation, suppliers of equipment, materials and reagents, in vitro method users (e.g., testing laboratories, large industries and small to medium enterprises), sponsors, receiving authorities and GLP monitoring authorities.Guidance for improved practice: Besides the elements necessary for good scientific work in discovery, additional requirements, such as documentation, ownership, identity and genetic make-up, related to the in vitro method and the test system, are key for their in vitro method acceptance at regulatory level.Recommendations are given for several of the target groups on how to put into practice their responsibilities for facilitating the development and implementation of in vitro methods for regulatory use.

Key message: To realise fully the potential of in vitro methods and allowing them to become a key tool for a new way of doing toxicology, they need to be developed and applied in a way that scientific integrity and quality is assured.Key content: Discusses quality assurance versus quality control, quality risk-based assessment and quality control requirements for development and implementation of in vitro methods, the types of documentation needed and quality considerations regarding the integrity of the data.Guidance for improved practice: Control charts can be used as a powerful and simple statistical tool to help routinely monitor the quality of any quantitative process and to determine if the process is in a state of control.Recommendations for basic quality risk assessment questions and applicability of integrity checks on cell and tissue cultures are described.

Key message: In vitro cell and tissue culture facilities should be fit for purpose and a detailed understanding of the work flow for the in vitro method related processes is essential. The separation of specific laboratory functions and elements that can adversely impact in vitro method work need to be understood.Key content: Elaborates safety, safety risk assessment and management including descriptions of Risk Groups and Biosafety Level requirements, proper facility design to ensure integrity of the cell and tissue cultures, the in vitro method itself and the resulting data.Guidance for improved practice: This chapter describes guidance on level of separation to avoid cross-contamination and quarantine measures for new test systems. A flow diagram indicating movement of staff, materials and reagents, test systems and test and reference items, and waste collections shows what processes need to be separated.Recommendations for classification of infective microorganisms, laminar flow biological safety cabinets and biosafety levels, are given.

Key message: Apparatus, including validated computerised systems, should be regularly maintained, calibrated and validated (if required). Material and reagents should be purchased from well-established sources to ensure the integrity and reliability of the in vitro method results.Key content: Quality requirements for equipment, material and reagents (e.g., use of serum, alternatives to the use of animal sourced serum, antibiotics, special media, certificate of analysis, stability and traceability) are detailed.Guidance for improved practice: By detailing the diversity in availability of in vitro related materials and reagents the reader can identify for his/her work their advantages and limitations.Recommendations are given to reduce experimental variability and increase within- and between-laboratory reproducibility by understanding the material and reagents you are working with and to take care that calibrated apparatus performance checks are carried out and operation limits are set adequately.

Key message: With the advances in science and technology a variety of different cell and tissue culture-based test systems have been developed but only few have been used in regulatory-approved test guideline methods due to reliability issues caused by a variety of elements described in this chapter.Key content: Elaborates on Good Cell Culture Practice logistics, cryostorage, handling, identification, containment, authentication and characterisation of the test system (e.g., cell lines, stem cells, primary cells, engineered tissues, etc.) already at the development stage.Guidance for improved practice: Processes for checking test system identity and characteristics, comparison of ultra-low cryostorage methods and good subculture, cryopreservation and banking practices are given.Recommendations are given for cell and tissue sourcing, contaminants screening, test system biomarkers and functional tests, since it may have influence on various aspects of the in vitro method.

Key message: The preparation and characterisation of test, reference and control items and their interaction with the in vitro environment should be well understood so as to ensure the acquisition of reliable and relevant results. Key content: Described are test item (characterisation, solubility and handling), test system and test item interaction and biokinetics during development to ensure test item compatibility and correct and reliable exposure.Guidance for improved practice: More detailed information on solubility determination methods; the limitations of test items for which the method is suitable will allow the reader to choose the most suitable approach for his/her particular needs.Recommendations Identify suitable reference and control items to avoid interference of the test, reference and/or control items with the in vitro method

Key message: Standard Operating Procedures (SOPs) and the accompanying forms, templates or worksheets should be written and prepared in a way that they will form the tools to simplify the work of the user when carrying out an in vitro method study.Key content: The chapter elaborates on the correct documentation of in vitro methods for routine testing including requirements for clear and concise SOPs.Guidance for improved practice: The evolution of a non-routine in vitro method to a routine in vitro method is described in a step-wise manner.Recommendations to derive a set of clear, well-written in vitro method SOPs are given.

Key message: In vitro method developers need to ensure that in vitro methods they design will produce good quality data, i.e. fit for purpose, thanks to a stringent assessment of the performance of the method.Key content: Elements of experimental design and how to determine the performance of a method are detailed, including aspects of plate layout, data analysis, and in-house method validation, including the assessment of linearity, range, accuracy, etc.Guidance for improved practice: Details are given to increase the reliability of endpoint calculations when multiple independent experiments are run and to use tools to quantify performance characteristics.Recommendations are given to in vitro method developers on how to increase the possibility of adoption of their method for regulatory purposes.

Key message: Good reporting of in vitro methods can only be achieved when all important details are recorded in a way that allows others to reproduce the work or reconstruct fully the in vitro method study.Key content: Guidance is given on publishing and reporting of in vitro method studies and on data reporting for regulatory purposes.Guidance for improved practice: Examples and available sources for scientific data management are detailed to promote more transparency and openness from scientists to avoid issues related to reproducibility of data but also to stimulate electronic data sharing for a variety of research and safety assessment purposes.Recommendations are given to not only publish or make available the in vitro method results but also all the related documents and the changes that have been introduced to improve the method and the rational for them.

Key message: Before collecting data from in vitro methods it is important to assess the format of collection, the complexity involved and requirements for traceability, storage, verification and transmission of data.Key content: The chapter gives insight on what key records and materials to archive and retain. It also details adequate document and record management of processes and the traceability of origin of materials.Guidance for improved practice: Data integrity arrangements must be in place and structured methods and essential process components are described for both paper-based and electronic data to ensure that the collected in vitro method data are attributable, legible, contemporaneous, original and accurate.Recommendations are detailedfor the necessary procedures related to retention, archiving, retrieval, backup and restoration for all target groups involved in the in vitro method lifecycle.