Survey on “Worldwide survey towards the use of molecular methods in parentage and diagnostic analyses”
The page summarises the Survey on “Worldwide survey towards the use of molecular methods in parentage and diagnostic analyses” (Molecular methods in parentage analyses).
Information on the international state of the art was collected through a questionnaire disseminated thanks to the active participation of ICAR and its Working Group. The results of the survey were shown at the 2004 ICAR meeting in Sousse. The questionnaire gave clear indication of a worldwide trend towards the use of molecular methods in parentage and diagnostic analyses.
Below is a proposal of requirements ICAR should consider for the accreditation of laboratories performing DNA analyses. Lab characteristics are to be tested against these and only laboratories meeting all minimum requirements to be accredited.
The key issues to be considered for accreditation and exchange of information are the following:
- Education, training and experience of the head of the laboratory: a Ph. D., MSC degree with at least two year experience or a Bachelor/University degree with at least three year experience should supervise the laboratory responsible for molecular analyses. All degrees are intended in scientific disciplines comprising courses related to DNA analysis (e.g. molecular biology, biochemistry, molecular genetics, chemistry, etc.)
- Ph. D. with one year experience
- Master with two year experience
- Bachelor with three year experience (Minimum requirement)
- Other (no accreditation)
- Experience of operators: molecular analyses need experienced operators to be correctly interpreted and to distinguish between artefacts and real results. At least one operator with at least two year experience should be required.
- y≥2 (Minimum requirement)
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- Y<2 (no accreditation)
- Analytical methods (protocols and procedures, quality checks): Homogeneity of procedures and quality check is more important than homogeneity in protocols, since these are generally optimised independently by each laboratory. Nevertheless main reagents (e.g. primers, antibodies, buffers, amplification condition etc.) are to be described by laboratories. A test not disclosed to third parties and that cannot be repeated in at least one independent lab, cannot be accredited by ICAR. Standard procedures for 1) handling of samples, from reception throughout the processing phase to the storing or disposal 2) storing and retrieving of information 2) avoiding cross-contaminations should be clearly defined by labs. In addition, systematic use of standard reference samples and measurement of repeatability of results on a subset of data should be routinely introduced in each lab.
- Protocol for handling of samples from arrival to disposal
- Protocol for storing and retrieving information
- Protocol for control of cross-contamination
- Protocol for error and repeatability checking
- Equipments: labs should have at least some months experience on equipments introducing high innovation in the way molecular analyses are accomplished. A relevant amount of data should be produced in duplicate using old and new technologies, to test for the reliability of the equipment and the appropriate training of operators. Equipment should be regularly controlled and maintained by authorised technical personnel.
- Type of Equipment
- Date of purchase
- Date of last revision
- Certification: Laboratories to be accredited should have international or national certification (e.g. ISO certification) and routinely follow Good Laboratory Practices.
- International certification
- National certification (minimum requirement)
- No certification (no accreditation)
- Participation and performance in ring-tests: participation to ring test (national and international) is an indicator that data quality and quality check have a relevant importance within lab and that the laboratory aims at implementing its performances through comparison and exchange with other institutions working in the same field. Comparison may result impossible for some tests, due to patents, not disclosure of genetic information etc. The participation in at least two comparison tests may be required for accreditation. Since ring test performance represents key information for the accreditation of laboratories, the disclosure of performance will become a must for ICAR accreditation. The threshold may be set quite lax initially (e.g. 10% error rate), to become progressively more strict.
- ≥ 2 international ring test
- < 2 international ring test
- performance in international ring test
- ≥ 2 national ring test (minimum requirement)
- < 2 national ring test
- performance in national ring test
- No ring test (no accreditation)
- Use of recommended ISAG/FAO marker sets: The use of a common set of markers is to be highly recommended, since this will make comparison between labs as well as exchange of experiences on the behaviour and performance of specific loci possible. Also, this will facilitate the use of a common standard nomenclature and permit the use and comparison of results obtained on a shared set of standard DNA samples.
- ISAG marker set
- Additional markers (please, specify)
- Nomenclature: The adoption of a standard nomenclature is to be highly recommended, these both for microsatellite allele calling and for disease or production gene variants. Nomenclature should adhere to existing official rules, when existing, or to widely accepted rules or to nomenclature proposed by the inventor/discoverer, in the case of new technologies or new loci.
- Other (specify) (no accreditation)
- Special cases: Some assays may represent special cases to be discussed on a case by case basis (e.g. patented assays, confidential information, new technologies, etc.).
Among these, in our opinion five issues have the highest priority, these are:
- education and experience of supervisor;
- experience of operators;
- national or international certification;
- participation and performance in ring tests;
- use of the official nomenclature;
The Genetic Analysis Working Group suggests following a stepwise approach and use cattle and parentage testing as pilot assay to be harmonised across countries and accredited to laboratories meeting the minimum standards. Stated that the strategy of spreading DNA standardization among ICAR members was already approved, the task force proposes that the following steps are therefore need to be taken in order to have an efficient and smooth application:
- To request, before December 31st 2005, to every member organizations a document stating the state of the art of the DNA lab they are utilizing for cattle and parentage testing with reference to the points a, b, c, d and e.
- At Kuopio ICAR meeting in June 2006, the situation was reviewed by the task force, also considering the possibility of scoring lab characteristics and decide on a minimal scoring treshold, with proposal to standardize the cattle and parentage testing and allowing from January 2007 only those parentage tests conformed to the points a, b, c, d and e and, if sensible, overcoming the minimum scoring threshold.
- At Kuopio it was also discussed further points to begin the harmonization among member Countries. Those points will be then reviewed at the ICAR meetings in 2007.
- At the following ICAR biennial Session to be held in 2008, new issues beyond cattle and parentage test will be considered (other species, applications, molecular technologies).