title: Bivariate statistical approach to evaluate laboratory performance by analysis of standard curves in an External Quality Assurance program for quantitative assays based on real-time PCR with Taq-Man probes.
abstract: Recently a revolutionary technique for quantitative PCR determination was introduced in diagnostic laboratories. To determine the influence of technical variability on the reliability of the quantitative assay, it is crucial to use External Quality Assurance (EQA) programs. An EQA program was developed in Italy to check the analytical performance of real-time PCR procedures based on Taq-Mantrade mark probes. This article suggests a new statistical approach to discriminate, using a bivariate technique, laboratory performance that appears to be questionable, by separately considering the two main features of the standard curve: analytical sensitivity and efficiency. Furthermore, specific indexes to evaluate the impact of these two features on the determination of the initial number of molecules are given to help to improve the assay procedure.
authors.affiliation: Istituto di Statistica Medica e Biometria, Università degli Studi di Milano, Milan, Italy. giuseppe.reina@unimi.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Reina
authors.forename: Claudio
authors.initials: C
authors.lastname: Orlando
authors.forename: Paola
authors.initials: P
authors.lastname: Rebora
authors.forename: Federico
authors.initials: F
authors.lastname: Ambrogi
authors.forename: Claudia
authors.initials: C
authors.lastname: Casini Raggi
authors.forename: Paolo
authors.initials: P
authors.lastname: Verderio
authors.forename: Ettore
authors.initials: E
authors.lastname: Marubini
mesh_terms: D002624:Chemistry, Clinical / Q000592:standards*; D015342:DNA Probes / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D016133:Polymerase Chain Reaction / Q000592:standards*; D011786:Quality Control; D012015:Reference Standards; D013223:Statistics as Topic; D019914:Taq Polymerase / Q000378:metabolism*; D013997:Time Factors
chemical_list: D015342:DNA Probes; D019914:Taq Polymerase