title: Sample-to-answer on molecular diagnosis of bacterial infection using integrated lab--on--a--disc.
abstract: Sepsis by bacterial infection causes high mortality in patients in intensive care unit (ICU). Rapid identification of bacterial infection is essential to ensure early appropriate administration of antibiotics to save lives of patients, yet the present benchtop molecular diagnosis is time-consuming and labor-intensive, which limits the treatment efficiency especially when the number of samples to be tested is extensive. Therefore, we hereby report a microfluidic platform lab-on-a-disc (LOAD) to provide a sample-to-answer solution. Our LOAD customized design of microfluidic channels allows automation to mimic sequential analytical steps in benchtop environment. It relies on a simple but controllable centrifugation force for the actuation of samples and reagents. Our LOAD system performs three major functions, namely DNA extraction, isothermal DNA amplification and real-time signal detection, in a predefined sequence. The disc is self-contained for conducting sample heating with chemical lysis buffer and silica microbeads are employed for DNA extraction from clinical specimens. Molecular diagnosis of specific target bacteria DNA sequences is then performed using a real-time loop-mediated isothermal amplification (RT-LAMP) with SYTO-9 as the signal reporter. Our LOAD system capable of bacterial identification of Mycobacterium tuberculosis (TB) and Acinetobacter baumanii (Ab) with the detection limits 103cfu/mL TB in sputum and 102cfu/mL Ab in blood within 2h after sample loading. The reported LOAD based on an integrated approach should address the growing needs for rapid point-of-care medical diagnosis in ICU.
authors.affiliation: Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: J
authors.initials: J
authors.lastname: Loo
authors.affiliation: Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: H C
authors.initials: HC
authors.lastname: Kwok
authors.affiliation: Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: C C H
authors.initials: CCH
authors.lastname: Leung
authors.affiliation: Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: S Y
authors.initials: SY
authors.lastname: Wu
authors.affiliation: Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: I L G
authors.initials: ILG
authors.lastname: Law
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Y K
authors.initials: YK
authors.lastname: Cheung
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Cheung
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: M L
authors.initials: ML
authors.lastname: Chin
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: P
authors.initials: P
authors.lastname: Kwan
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: M
authors.initials: M
authors.lastname: Hui
authors.affiliation: Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: S K
authors.initials: SK
authors.lastname: Kong
authors.affiliation: Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong. Electronic address: hpho@ee.cuhk.edu.hk.
authors.forename: H P
authors.initials: HP
authors.lastname: Ho
mesh_terms: D040981:Acinetobacter baumannii / Q000302:isolation & purification* / Q000472:pathogenicity; D015374:Biosensing Techniques; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D046210:Microfluidic Analytical Techniques; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification* / Q000472:pathogenicity; D009930:Organic Chemicals / Q000737:chemistry; D018805:Sepsis / Q000175:diagnosis / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D009930:Organic Chemicals; C103389:SYTO 9
keywords: Infectious disease diagnosis; Lab-­on-­a-disc; Loop-­mediated isothermal amplification; Sample-to-answer