Australasian Biotechnology (backfiles) AusBiotech ISSN: 1036-7128 Vol. 12, Num. 2, 2002, pp. 31

Australasian Biotechnology, Vol. 12 No. 2, 2002, pp. 31

BIOTECHNOLOGY RESEARCH

ADDRESSING THE ISSUE OF ACCURATE MEASUREMENT WITHIN BIOLOGICAL SYSTEMS

Kate R. Griffiths, Lina Partis, David Croan and Kerry R. Emslie

Research and Development Section, Australian Government Analytical Laboratories, 1 Suakin Street, Pymble, NSW, 2073, Australia. Email: kate.griffiths@agal.gov.au

Code Number: au02011

Research in the fields of life sciences and biotechnology has expanded rapidly in the last decade and new technologies are constantly being explored. As a number of these technologies make the transition into the routine laboratory, there is a significant challenge associated with the accuracy of biology-based measurement. This need for accuracy can be clearly demonstrated in the field of nucleic acid testing.

In the medical field, nucleic acid detection techniques are replacing many conventional laboratory methods, such as cell and pathogen culture, immunoassays and protein biochemistry (NPAAC Guidelines). Method accuracy is critical for the correct and timely diagnosis or prediction of disease.

As a trade issue, a number of countries have implemented labelling requirements for genetically modified (GM) food if any ingredient contains more than a certain percentage (w/w) of GM material. Robust methods are required to ensure compliance. Many studies have been carried out to determine method and laboratory variability. In early 2000, the Food Analysis Performance Assessment Scheme (FAPAS), Central Science Laboratories, UK, initiated a proficiency testing scheme for detection of GM food. Worldwide, over 70 laboratories submitted results for initial rounds of this series. While the vast majority of laboratories used polymerase chain reaction (PCR) for detection of GM food, the DNA extraction process varied considerably, as did the method for PCR analysis. There were significant discrepancies in reporting of both qualitative and quantitative results. Up to 26% of results for non-GM food samples were reported as false positives while up to 8% of GM food samples were reported as false negatives. Results for quantitation were even more varied. In practical terms this means that there is a distinct possibility of trade disputes in this area due to inability to produce reliable and reproducible results.

Another study raises concern for accuracy across all areas of PCR-based testing. This study investigated the effects of inter and intra-block variability on the performance of thermal cyclers used for PCR. The variability of results highlighted the importance of temperature calibration of PCR instruments to achieve accurate and reproducible results (Saunders et al, 2001). How many laboratories, either diagnostic or research, routinely check thermal cycler temperatures?

These studies point to the need for development of quality control and quality assurance protocols to address the critical points and to demonstrate the validity of DNA technologies and associated measurement. In addition, specific criteria need to be developed for assessment of method precision, accuracy, ruggedness and bias' suitable reference materials will also be required.

Metrology is the science of measurement and can assist in providing these needs. Metrology includes all matters, both theoretical and practical, that impact on measurements (150, 1993). The relatively new science of biology-based metrology has been referred to as Biometrology (Parkes, 2000). Biometrology has application in fields as diverse as diagnostics, proteomics, forensic DNA, and tissue engineering. For several years, the UK has contributed significantly in this area through the government-funded National Measurement System (NMS) Valid Analytical Measurement (VAM) Program which has included projects on nucleic acid measurement. More recently, a NMS 'Measurements for Biotechnology' Program has been announced to increase the ability of UK companies to exploit the biotechnology emerging from the science base. A similar program is operated in the USA through the National Institute of Standards and Technology (NIST) In response to the growing national and international needs to address biological measurement, the Australian Government Analytical Laboratories (AGAL) has initiated a new research program to develop a support infrastructure for traceable biological measurement. This program will enable AGAL to participate in future collaborative studies and discussions in order to remain abreast of international development in this area. Input will be sought from Australian industry, university and government stakeholders in order to develop a program that reflects the needs of Australia and complements international initiatives.

References

• Central Science Laboratories (2000-1) FAPAS Series 23 Rounds 1-4. Genetically modified organisms. Report Nos. 2301-2304.
• International Organisation for Standardisation (1993) International Vocabulary ofBasic and General Terms in Metrology. 2nd Edition. National Pathology
• Accreditation Advisory Council (NPAAC) (2000) Laboratory accreditation standards and guidelines/or nucleic acid detection techniques. Commonwealth Department of Health and Aging.
• Parkes, H.C. (2000) Metrology issues in analytical molecular biology. 6th Meeting of the CCQM, Bureau International des Poids et Mesures, Sèvres, Frances.
• Saunders, D.C., Dtikes,J., Parkes, HG. & Cornett, J.H. (2001) lnterlaboratory studyon thermal cycler performance in controlledPCR and random amplified polymorphicDNA analyses. Clinical Chemistry 47, 47-55.

AGAL is the Australian Government's principal agency for the provision of analytical services in chemistry, microbiology (including molecular biology) and materials and building science. AGAL has major laboratories in Sydney, Melbourne and Perth. Web site www.agal.gov.au

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