% % This file was created by the TYPO3 extension % bib % --- Timezone: CET % Creation date: 2024-03-29 % Creation time: 00-00-28 % --- Number of references % 4 % @Article { Klauenberg2015, title = {Informative prior distributions for ELISA analyses}, journal = {Biostatistics}, year = {2015}, month = {1}, day = {1}, volume = {16}, number = {3}, pages = {454--64}, abstract = {Immunoassays are capable of measuring very small concentrations of substances in solutions and have an immense range of application. Enzyme-linked immunosorbent assay (ELISA) tests in particular can detect the presence of an infection, of drugs, or hormones (as in the home pregnancy test). Inference of an unknown concentration via ELISA usually involves a non-linear heteroscedastic regression and subsequent prediction, which can be carried out in a Bayesian framework. For such a Bayesian inference, we are developing informative prior distributions based on extensive historical ELISA tests as well as theoretical considerations. One consideration regards the quality of the immunoassay leading to two practical requirements for the applicability of the priors. Simulations show that the additional prior information can lead to inferences which are robust to reasonable perturbations of the model and changes in the design of the data. On real data, the applicability is demonstrated across different laboratories, for different analytes and laboratory equipment as well as for previous and current ELISAs with sigmoid regression function. Consistency checks on real data (similar to cross-validation) underpin the adequacy of the suggested priors. Altogether, the new priors may improve concentration estimation for ELISAs that fulfill certain design conditions, by extending the range of the analyses, decreasing the uncertainty, or giving more robust estimates. Future use of these priors is straightforward because explicit, closed-form expressions are provided. This work encourages development and application of informative, yet general, prior distributions for other types of immunoassays.}, tags = {Regression, 8.42, ELISA}, web_url = {http://biostatistics.oxfordjournals.org/content/16/3/454}, ISSN = {1468-4357}, DOI = {10.1093/biostatistics/kxu057}, author = {Klauenberg, K and Walzel, M and Ebert, B and Elster, C} } @Article { Bunk, title = {CCQM-P58.1: Immunoassay Quantitation of Human Cardiac Troponin I.}, journal = {Metrologia}, year = {2015}, month = {1}, day = {8}, volume = {52}, number = {1A}, pages = {08006}, abstract = {The CCQM study P58.1 assessed the equivalence of immunoassay measurements between participating NMIs. The aim of P58.1 was to demonstrate the equivalence of immunoassay measurements to determine the mass concentration of the clinically-relevant protein human cardiac troponin I (cTnI) present at low concentration relative to the protein concentration of the sample matrix. The measurement equivalence was assessed using traceability to a common certified reference material. To quantify cTnI, participants used a homogeneous sandwich-based immunoassay with an enzymatic amplification step. The antibody format consisted of a single capture and single detection antibody (referred to as 1 + 1), both were supplied to study participants. In the previous P58 study, ELISA measurement results were compared between laboratories which all used common ELISA reagents (including 96-well plates), samples, a standard for the production of calibrants, and a detailed ELISA protocol, which were supplied by a single laboratory. The P58.1 study only utilized common samples, a standard of the production of calibrants, and a set of monoclonal antibodies (mAbs). Because much of the experimental procedure for the P58 study was essentially standardized across participating labs, the study primarily highlighted between-laboratory differences in plate sampling designs and in plate reader response. As the participants in the P58.1 study had to produce most of their own analytical reagents and develop their own measurement procedure, the study provides a better evaluation of the equivalence of ELISA measurements between the participating laboratories. Main text. To reach the main text of this paper, click on Final Report [http://www.bipm.org/utils/common/pdf/final_reports/QM/P58/CCQM-P58.1.pdf] The final report has been peer-reviewed and approved for publication by CCQM.}, tags = {8.42,ELISA}, web_url = {http://stacks.iop.org/0026-1394/52/i=1A/a=08006}, DOI = {10.1088/0026-1394/52/1A/08006}, author = {Bunk, D and Noble, J and Knight, A E and Wang, L and Klauenberg, K and Walzel, M and Elster, C} } @Inbook { Voigt2008, title = {Validierung eines ’Fluorescent Enzyme Linked Immuno Sandwich Assay’ (ELISA)}, year = {2015}, month = {1}, day = {1}, volume = {PTB Mitteilungen 118}, pages = {255-260}, tags = {ELISA}, author = {Voigt, J and Ebert, B and Hoffman, A and Macdonald, R} } @Article { Klauenberg2011, title = {Bayesian analysis of an international ELISA comparability study}, journal = {Clinical chemistry and laboratory medicine : CCLM / FESCC}, year = {2011}, volume = {49}, number = {9}, pages = {1459--68}, abstract = {BACKGROUND: Immunoassays are biochemical tests applied to measure even very small amounts of substance using the highly specific binding between an antibody and its antigen. They have a wide range of applications. The measurement however, might be associated with substantial uncertainty; this can have significant consequences for any diagnosis, or clinical decision. An international comparability study was thus performed to assess the sources of uncertainty involved in the estimation of a protein cytokine concentration using a fluorescent ELISA. METHODS: In contrast to the original publication for this international comparability study, we reanalyse the data using Bayesian inference. This provides a statistically coherent approach to estimate ELISA concentrations and their associated uncertainties. RESULTS: The Bayesian uncertainties of individual ELISAs and laboratory estimates are considerably larger than previously reported uncertainties. The average concentrations estimated here differ from the ones estimated by each study participant. In general, this leads to different conclusions about the study. In particular, the inter- and intra-laboratory consistency is increased, and repeatability problems occur for fewer laboratories. CONCLUSIONS: Decisions which are based on plausible ranges of measurements (such as credible intervals), are generally superior to those solely based on point estimates (such as the mean). Reliable uncertainties are thus vital, and not only in metrology. In this paper, a general method is developed to derive concentration estimates and valid uncertainties for ELISAs. Guidance on applying this Bayesian method is provided and the importance of reliable uncertainties associated with ELISAs is underlined. The applicability and virtues of the presented method are demonstrated in the context of an international comparability study.}, keywords = {Bayes Theorem,Calibration,ELISA,Enzyme-Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assay: standards,Internationality,Reference Standards,Regression,Uncertainty}, tags = {8.42, ELISA}, web_url = {http://www.degruyter.com/view/j/cclm.2011.49.issue-9/cclm.2011.648/cclm.2011.648.xml}, ISSN = {1437-4331}, DOI = {10.1515/CCLM.2011.648}, author = {Klauenberg, K and Ebert, B and Voigt, J and Walzel, M and Noble, J E and Knight, A E and Elster, C} }