Validation of assembled nucleic acid-based tests in diagnostic microbiology laboratories

Medical microbiology and virology laboratories use nucleic acid tests (NAT) to detect genomic material of infectious organisms in clinical samples. Laboratories choose to perform assembled (or in-house) NAT if commercial assays are not available or if assembled NAT are more economical or accurate. One reason commercial assays are more expensive is because extensive validation is necessary before the kit is marketed, as manufacturers must accept liability for the performance of their assays, assuming their instructions are followed. On the other hand, it is a particular laboratory's responsibility to validate an assembled NAT prior to using it for testing and reporting results on human samples. There are few published guidelines for the validation of assembled NAT. One procedure that laboratories can use to establish a validation process for an assay is detailed in this document. Before validating a method, laboratories must optimise it and then document the protocol. All instruments must be calibrated and maintained throughout the testing process. The validation process involves a series of steps including: (i) testing of dilution series of positive samples to determine the limits of detection of the assay and their linearity over concentrations to be measured in quantitative NAT; (ii) establishing the day-to-day variation of the assay's performance; (iii) evaluating the sensitivity and specificity of the assay as far as practicable, along with the extent of cross-reactivity with other genomic material; and (iv) assuring the quality of assembled assays using quality control procedures that monitor the performance of reagent batches before introducing new lots of reagent for testing.

Effect of sequence variation in Plasmodium falciparum Histidine-Rich protein 2 on binding of specific monoclonal antibodies: Implications for rapid diagnostic tests for malaria

This Article Right arrow Full Text Right arrow Full Text (PDF) Right arrow Supplemental material Right arrow Alert me when this article is cited Right arrow Alert me if a correction is posted Services Right arrow Similar articles in this journal Right arrow Similar articles in PubMed Right arrow Alert me to new issues of the journal Right arrow Download to citation manager Right arrow Reprints and Permissions Right arrow Copyright Information Right arrow Books from ASM Press Right arrow MicrobeWorld Citing Articles Right arrow Citing Articles via HighWire Right arrow Citing Articles via Google Scholar Google Scholar Right arrow Articles by Lee, N. Right arrow Articles by McCarthy, J. Right arrow Search for Related Content PubMed Right arrow PubMed Citation Right arrow Articles by Lee, N. Right arrow Articles by McCarthy, J. Right arrow Pubmed/NCBI databases * Substance via MeSH Previous Article | Next Article Journal of Clinical Microbiology, August 2006, p. 2773-2778, Vol. 44, No. 8 0095-1137/06/$08.00+0 doi:10.1128/JCM.02557-05 Copyright © 2006, American Society for Microbiology. All Rights Reserved. Effect of Sequence Variation in Plasmodium falciparum Histidine- Rich Protein 2 on Binding of Specific Monoclonal Antibodies: Implications for Rapid Diagnostic Tests for Malaria{dagger} Nelson Lee,1,2 Joanne Baker,2 Kathy T. Andrews,1 Michelle L. Gatton,1,3 David Bell,4 Qin Cheng,2,3 and James McCarthy1* Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research and School of Population Health, University of Queensland, Queensland, Australia,1 Department of Drug Resistance and Diagnostics, Australian Army Malaria Institute, Brisbane, Australia,2 Malaria Drug Resistance and Chemotherapy, Queensland Institute of Medical Research, Queensland, Australia,3 World Health Organization, Regional Office for the Western Pacific, Manila, Philippines4 Received 8 December 2005/ Returned for modification 23 February 2006/ Accepted 26 May 2006 The ability to accurately diagnose malaria infections, particularly in settings where laboratory facilities are not well developed, is of key importance in the control of this disease. Rapid diagnostic tests (RDTs) offer great potential to address this need. Reports of significant variation in the field performance of RDTs based on the detection of Plasmodium falciparum histidine-rich protein 2 (HRP2) (PfHRP2) and of significant sequence polymorphism in PfHRP2 led us to evaluate the binding of four HRP2-specific monoclonal antibodies (MABs) to parasite proteins from geographically distinct P. falciparum isolates, define the epitopes recognized by these MABs, and relate the copy number of the epitopes to MAB reactivity. We observed a significant difference in the reactivity of the same MAB to different isolates and between different MABs tested with single isolates. When the target epitopes of three of the MABs were determined and mapped onto the peptide sequences of the field isolates, significant variability in the frequency of these epitopes was observed. These findings support the role of sequence variation as an explanation for variations in the performance of HRP2-based RDTs and point toward possible approaches to improve their diagnostic sensitivities

Reflections on the centrality of power in medical sociology: an empirical test and theoretical elaboration

This paper explores the contemporary relevance of sociological theorisations centred on medical power, including the medical dominance and deprofessionalisation theses. To achieve this it examines two issues that have been tentatively linked to the relative decline of the power and autonomy of biomedicine - complementary and alternative medicine (CAM) and the Internet-informed patient. Drawing on these two different but interconnected social phenomena, this paper reflects on the potential limitations of power-based theorisations of the medical profession and its relationship to patients and other non-biomedically situated professional groups. It is argued that power-based conceptual schemas may not adequately reflect the non-linear and complex strategic adaptations that are occurring among professional groups.

An exploration of the needs and goals of the health professional and patient in a medical consultation

This Study is the first phase of a three-phase study continuing over three years. Twent)' health professionals from different disciplinary backgrounds (medical doctors, nurses, allied health professionals) and 20 patients across a range of medical condidons, education, gender, and socio-economic backgrounds, pardcipated in one-on-one semi-structured interviews. Participants described their experiences and percepdons of both effecdve and sadsfying medical consultations and dissadsf)'ing and ineffecdve ones. They also discussed their individual goals and needs in the consultation process. Results indicated that while there were some similarides in consultation goals and needs between health professionals, there were also clear differences across the different discipUnes. In addition, there were clear differences in goals and needs across the twenty padents. These findings are discussed within the framework of communicadon accommodadon theor}' (CAT) and the linguisdc model of padent pardcipadon (LMOPP) and focus on understanding the different dynamics that underpin varying health professional and padent interacdons.

Deregulation, competition policy and intra-professional contests in medical education

This paper investigates how government policy directions embracing deregulation and market liberalism, together with significant pre-existing tensions within the Australian medical profession, produced ground breaking change in the funding and delivery of medical education for general practitioners. From an initial view between and within the medical profession, and government, about the goal of improving the standards of general practice education and training, segments of the general practice community, particularly those located in rural and remote settings, displayed increasingly vocal concerns about the approach and solutions proffered by the predominantly urban-influenced Royal Australian College of General Practitioners (RACGP). The extent of dissatisfaction culminated in the establishment of the Australian College of Rural and Remote Medicine (ACRRM) in 1997 and the development of an alternative curriculum for general practice. This paper focuses on two decades of changes in general practice training and how competition policy acted as a justificatory mechanism for putting general practice education out to competitive tender against a background of significant intra-professional conflict. The government's interest in increasing efficiency and deregulating the 'closed shop' practices of professions, as expressed through national competition policy, ultimately exposed the existing antagonisms within the profession to public view and allowed the government some influence on the sacred cow of professional training. Government policy has acted as a mechanism of resolution for long standing grievances of the rural GPs and propelled professional training towards an open competition model. The findings have implications for future research looking at the unanticipated outcomes of competition and internal markets.