title: A novel approach for evaluating the performance of real time quantitative loop-mediated isothermal amplification-based methods.
abstract: Molecular diagnostic measurements are currently underpinned by the polymerase chain reaction (PCR). There are also a number of alternative nucleic acid amplification technologies, which unlike PCR, work at a single temperature. These 'isothermal' methods, reportedly offer potential advantages over PCR such as simplicity, speed and resistance to inhibitors and could also be used for quantitative molecular analysis. However there are currently limited mechanisms to evaluate their quantitative performance, which would assist assay development and study comparisons. This study uses a sexually transmitted infection diagnostic model in combination with an adapted metric termed isothermal doubling time (IDT), akin to PCR efficiency, to compare quantitative PCR and quantitative loop-mediated isothermal amplification (qLAMP) assays, and to quantify the impact of matrix interference. The performance metric described here facilitates the comparison of qLAMP assays that could assist assay development and validation activities.
authors.affiliation: LGC, Queens Road, Teddington, UK.
authors.forename: Gavin J
authors.initials: GJ
authors.lastname: Nixon
authors.affiliation: Awapatent A/S, Copenhagen, Denmark.
authors.forename: Helle F
authors.initials: HF
authors.lastname: Svenstrup
authors.affiliation: LGC, Queens Road, Teddington, UK.
authors.forename: Carol E
authors.initials: CE
authors.lastname: Donald
authors.affiliation: Medicine Clinical Board, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Carder
authors.affiliation: Institute for Women's Health, University College London, London, UK.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Stephenson
authors.affiliation: Department of Clinical Microbiology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Morris-Jones
authors.affiliation: LGC, Queens Road, Teddington, UK.
authors.forename: Jim F
authors.initials: JF
authors.lastname: Huggett
authors.affiliation: LGC, Queens Road, Teddington, UK.
authors.forename: Carole A
authors.initials: CA
authors.lastname: Foy
keywords: Cq, quantification cycle; Diagnostics; IDT, isothermal doubling time; Isothermal nucleic acid amplification; MIQE, minimum information for the publication of quantitative real-time PCR experiments; NAA, nucleic acid amplification; Quantitative LAMP; Quantitative real time PCR; Standardisation; Tt, threshold time; qLAMP, quantitative loop-mediated amplification; qPCR, quantitative real-time polymerase chain reaction; td, doubling time