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Chaffin JD, Barker KB, Bickman SR, Bratton JF, Bridgeman TB, Bhatia M, Buchholz SD, Bullerjahn GS, Johengen TH, Kang DW, Lewis GG, Lochhead MJ, Macdonald BM, Petrou CL, Platz M, Purcell H, Roser J, Seo Y, Siddiquee M, Snyder B, Taylor AT, Verhamme EM, Westrick JA. An assessment of a biosensor system for the quantification of microcystins in freshwater cyanobacterial blooms. Anal Biochem 2024; 687:115429. [PMID: 38113981 DOI: 10.1016/j.ab.2023.115429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/29/2023] [Accepted: 12/11/2023] [Indexed: 12/21/2023]
Abstract
Microcystin-producing cyanobacterial blooms are a global issue threatening drinking water supplies and recreation on lakes and beaches. Direct measurement of microcystins is the only way to ensure waters have concentrations below guideline concentrations; however, analyzing water for microcystins takes several hours to days to obtain data. We tested LightDeck Diagnostics' bead beater cell lysis and two versions of the quantification system designed to give microcystin concentrations within 20 min and compared it to the standard freeze-thaw cycle lysis method and ELISA quantification. The bead beater lyser was only 30 % effective at extracting microcystins compared to freeze-thaw. When considering freeze-thaw samples analyzed in 2021, there was good agreement between ELISA and LightDeck version 2 (n = 152; R2 = 0.868), but the LightDeck slightly underestimated microcystins (slope of 0.862). However, we found poor relationships between LightDeck version 2 and ELISA in 2022 (n = 49, slopes 0.60 to 1.6; R2 < 0.6) and LightDeck version 1 (slope = 1.77 but also a high number of less than quantifiable concentrations). After the quantification issues are resolved, combining the LightDeck system with an already-proven rapid lysis method (such as microwaving) will allow beach managers and water treatment operators to make quicker, well-informed decisions.
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Affiliation(s)
- Justin D Chaffin
- F.T. Stone Laboratory and Ohio Sea Grant, The Ohio State University, Put in Bay, Ohio 43456, USA; Bowling Green State University, Bowling Green, Ohio 43403, USA.
| | | | - Sarah R Bickman
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - John F Bratton
- LimnoTech, Inc. 501 Avis Dr., Ann Arbor Michigan 48108, USA
| | | | - Mudit Bhatia
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, Toledo, Ohio 43606, USA
| | - Seth D Buchholz
- Bowling Green State University, Bowling Green, Ohio 43403, USA
| | | | - Thomas H Johengen
- Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Dae-Wook Kang
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, Toledo, Ohio 43606, USA
| | - Gregory G Lewis
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - Michael J Lochhead
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - Brooks M Macdonald
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - Cassandra L Petrou
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - Michelle Platz
- LimnoTech, Inc. 501 Avis Dr., Ann Arbor Michigan 48108, USA
| | - Heidi Purcell
- Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jack Roser
- LightDeck Diagnostics, Inc., 5603 Arapahoe Ave, Boulder, Colorado 80303, USA
| | - Youngwoo Seo
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, Toledo, Ohio 43606, USA; Department of Chemical Engineering, University of Toledo, 3048 Nitschke Hall, Toledo, Ohio 43606, USA
| | - Mashuk Siddiquee
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, Toledo, Ohio 43606, USA
| | - Brenda Snyder
- Lake Erie Center, The University of Toledo, Oregon, Ohio 43616, USA
| | - Autumn T Taylor
- F.T. Stone Laboratory and Ohio Sea Grant, The Ohio State University, Put in Bay, Ohio 43456, USA
| | | | - Judy A Westrick
- Lumigen Instrument Center, Wayne State University, 5101Cass Ave., Detroit, Michigan 48202, USA
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Wilson CS, Vashi B, Genzor P, Gregory MK, Yau J, Wolfe L, Lochhead MJ, Papst P, Pettrone K, Blair PW, Krishnan S, Chenoweth JG, Clark DV. Point-of-care biomarker assay for rapid multiplexed detection of CRP and IP-10. SLAS Technol 2023; 28:442-448. [PMID: 37844868 DOI: 10.1016/j.slast.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/14/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Rapid and accurate measurements of immune protein markers are essential for diagnosis and treatment in all clinical settings. The recent pandemic has revealed a stark need for developing new tools and assays that could be rapidly used in diverse settings and provide useful information to clinicians. Here, we describe the development and test application of a novel one-step CRP/IP-10 duplex assay for the LightDeck platform capable of delivering reproducible and accurate measurements in under eight minutes. We used the optimized assay to measure CRP and IP-10 levels in human blood and serum samples from healthy, SARS-CoV-2 (COVID-19) positive, and influenza-like illness (ILI) presenting patients. Our results agreed with previously published analyte levels and enabled us to make statistically significant comparisons relevant to multiple clinical parameters. Our duplex assay is a simple and powerful tool for aiding prognostic decision-making in diverse settings.
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Affiliation(s)
- Claire S Wilson
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Bhavya Vashi
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Pavol Genzor
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Melissa K Gregory
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Jason Yau
- LightDeck Diagnostics, Inc., Boulder, CO, USA
| | | | | | - Phil Papst
- LightDeck Diagnostics, Inc., Boulder, CO, USA
| | - Kristen Pettrone
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Paul W Blair
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Subramaniam Krishnan
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Josh G Chenoweth
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
| | - Danielle V Clark
- The Austere environments Consortium for Enhanced Sepsis Outcomes (ACESO), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
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Bickman SR, Campbell K, Elliott C, Murphy C, O'Kennedy R, Papst P, Lochhead MJ. An Innovative Portable Biosensor System for the Rapid Detection of Freshwater Cyanobacterial Algal Bloom Toxins. Environ Sci Technol 2018; 52:11691-11698. [PMID: 30208702 DOI: 10.1021/acs.est.8b02769] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Harmful algal blooms in freshwater systems are increasingly common and present threats to drinking water systems, recreational waters, and ecosystems. A highly innovative simple to use, portable biosensor system (MBio) for the rapid and simultaneous detection of multiple cyanobacterial toxins in freshwater is demonstrated. The system utilizes a novel planar waveguide optical sensor that delivers quantitative fluorescent competitive immunoassay results in a disposable cartridge. Data are presented for the world's first duplex microcystin (MC)/cylindrospermopsin (CYN) assay cartridge using a combination of fluorophore-conjugated monoclonal antibodies as detector molecules. The on-cartridge detection limits of 20% inhibitory concentration (IC20) was 0.4 μg/L for MC and 0.7 μg/L for CYN. MC assay coverage of eight important MC congeners was demonstrated. Validation using 45 natural lake water samples from Colorado and Lake Erie showed quantitative correlation with commercially available laboratory-based enzyme linked immunosorbent assays. A novel cell lysis module was demonstrated using cyanobacteria cultures. Results show equivalent or better performance than the gold-standard but more tedious 3× freeze-thaw method, with >90% cell lysis for laboratory cultures. The MBio system holds promise as a versatile tool for multiplexed field-based cyanotoxin detection, with future analyte expansion including saxitoxin, anatoxin-a, and marine biotoxins.
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Affiliation(s)
- Sarah R Bickman
- MBio Diagnostics, Inc. , 5603 Arapahoe Ave , Boulder , Colorado 80303 , United States
| | - Katrina Campbell
- Institute for Global Food Security, School of Biological Sciences , Queen's University, Belfast , Stranmillis Road , Belfast , United Kingdom , BT9 5AG
| | - Christopher Elliott
- Institute for Global Food Security, School of Biological Sciences , Queen's University, Belfast , Stranmillis Road , Belfast , United Kingdom , BT9 5AG
| | - Caroline Murphy
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute , Dublin City University , Dublin 9 , Ireland
| | - Richard O'Kennedy
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute , Dublin City University , Dublin 9 , Ireland
| | - Philip Papst
- MBio Diagnostics, Inc. , 5603 Arapahoe Ave , Boulder , Colorado 80303 , United States
| | - Michael J Lochhead
- MBio Diagnostics, Inc. , 5603 Arapahoe Ave , Boulder , Colorado 80303 , United States
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Gerth‐Guyette E, Malacad CC, Demonteverde MP, Faulx D, Lochhead MJ, Lupisan SP, Leader BT, Tallo VL. Understanding user requirements to improve adoption of influenza diagnostics in clinical care within Metro Manila. Health Sci Rep 2018; 1:e75. [PMID: 30623098 PMCID: PMC6266513 DOI: 10.1002/hsr2.75] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 05/09/2018] [Accepted: 05/31/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND AND AIM Influenza diagnostics play a critical role informing in clinical management decisions and defining the global epidemiology of the disease to support public health responses. Use of influenza diagnostics within most low-income and middle-income countries remains limited, including in the Philippines, where they are currently used only for epidemiologic surveillance. The aim of this study was to define key considerations, including product characteristics, which may influence future adoption, uptake, and integration of influenza diagnostics into public and private clinical settings in this emerging Asian market. METHODS Our study was conducted using a convenience sample of public and private hospital laboratories in Metro Manila. A usability assessment was conducted that included interviews with decision-makers and direct observation of laboratory end users using 2 platforms representative of emerging diagnostic products: (1) a point-of-care antigen-based rapid immunoassay diagnostic test paired with a reader and (2) a molecular diagnostic platform intended for decentralized use. Data were analyzed to assess user errors and device failure modes with each platform and to determine key considerations related to product adoption and uptake. RESULTS The most difficult test step for most users on both platforms involved sample preparation. When deciding to adopt a new test, priority product attributes include performance, potential volume of demand from clinicians, equipment cost, and ease of use. Demand for new tests is likely going to be driven by clinicians, and policies and guidelines will be needed to support the introduction of new products. CONCLUSION Adoption of influenza diagnostics in Metro Manila is feasible but will require affordable products capable of satisfying needs for use in both epidemiologic surveillance and clinical management.
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Affiliation(s)
| | - Carol C. Malacad
- Research Institute for Tropical MedicineDepartment of HealthMetro ManilaPhilippines
| | - Ma Paz Demonteverde
- Research Institute for Tropical MedicineDepartment of HealthMetro ManilaPhilippines
| | | | | | - Socorro P. Lupisan
- Research Institute for Tropical MedicineDepartment of HealthMetro ManilaPhilippines
| | | | - Veronica L. Tallo
- Research Institute for Tropical MedicineDepartment of HealthMetro ManilaPhilippines
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Broger T, Basu Roy R, Filomena A, Greef CH, Rimmele S, Havumaki J, Danks D, Schneiderhan-Marra N, Gray CM, Singh M, Rosenkrands I, Andersen P, Husar GM, Joos TO, Gennaro ML, Lochhead MJ, Denkinger CM, Perkins MD. Diagnostic Performance of Tuberculosis-Specific IgG Antibody Profiles in Patients with Presumptive Tuberculosis from Two Continents. Clin Infect Dis 2017; 64:947-955. [PMID: 28362937 PMCID: PMC5848306 DOI: 10.1093/cid/cix023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 01/12/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Development of rapid diagnostic tests for tuberculosis is a global priority. A whole proteome screen identified Mycobacterium tuberculosis antigens associated with serological responses in tuberculosis patients. We used World Health Organization (WHO) target product profile (TPP) criteria for a detection test and triage test to evaluate these antigens. METHODS Consecutive patients presenting to microscopy centers and district hospitals in Peru and to outpatient clinics at a tuberculosis reference center in Vietnam were recruited. We tested blood samples from 755 HIV-uninfected adults with presumptive pulmonary tuberculosis to measure IgG antibody responses to 57 M. tuberculosis antigens using a field-based multiplexed serological assay and a 132-antigen bead-based reference assay. We evaluated single antigen performance and models of all possible 3-antigen combinations and multiantigen combinations. RESULTS Three-antigen and multiantigen models performed similarly and were superior to single antigens. With specificity set at 90% for a detection test, the best sensitivity of a 3-antigen model was 35% (95% confidence interval [CI], 31-40). With sensitivity set at 85% for a triage test, the specificity of the best 3-antigen model was 34% (95% CI, 29-40). The reference assay also did not meet study targets. Antigen performance differed significantly between the study sites for 7/22 of the best-performing antigens. CONCLUSIONS Although M. tuberculosis antigens were recognized by the IgG response during tuberculosis, no single antigen or multiantigen set performance approached WHO TPP criteria for clinical utility among HIV-uninfected adults with presumed tuberculosis in high-volume, urban settings in tuberculosis-endemic countries.
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Affiliation(s)
| | | | - Angela Filomena
- Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | | | - Stefanie Rimmele
- Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | | | - David Danks
- Department of Philosophy, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | | | | | | | | | | | | | - Thomas O Joos
- Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Maria L Gennaro
- Public Health Research Institute, Rutgers New Jersey Medical School, New Brunswick
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6
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Givens M, Weaver A, Bickman S, Logan C, Noormahomed EV, Patel S, Schooley RT, Benson CA, Lochhead MJ. Near patient CD4 count in a hospitalized HIV patient population. Cytometry B Clin Cytom 2015; 92:451-455. [PMID: 25917935 DOI: 10.1002/cyto.b.21248] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 04/03/2015] [Accepted: 04/14/2015] [Indexed: 11/06/2022]
Abstract
BACKGROUND Point-of-care (POC) CD4 T-cell counting is increasingly recognized as providing improved linkage-to-care during management of HIV infection, particularly in resource-limited settings where disease burden is highest. This study evaluated prototype POC CD4 T-cell counters from MBio Diagnostics in the context of low CD4 count, hospitalized patients in Mozambique. This study measured system performance when presented with challenging, low count samples from HIV/AIDS patients with acute illnesses resulting in hospitalization. METHODS Forty whole blood samples were collected from donors on the medical service at Maputo Central Hospital and absolute CD4 counts were generated on the MBio CD4 system and a reference laboratory using flow cytometry. RESULTS The mean and median CD4 counts by the flow cytometry reference were 173 and 80 cells/µL, respectively. Correlation between the MBio CD4 System and the reference was good. Bland-Altman analysis showed a mean bias of +15 cells/µL (+9 to +21 cells/µL, 95% CI), and limits of agreement of -47 to 77 cells/µL. For samples with counts >100 cells/µL (N = 14), the mean coefficient of variation was 7.3%. For samples with counts <50 cells/µL, mean absolute bias of replicate samples was 4.8 cells/µL. When two MBio readers were compared, Bland-Altman bias was -4 cells/µL (-13 to +6 cells/µL, 95% CI), and limits of agreement of -63 and +55 cells/µL. CONCLUSIONS The MBio System holds promise as a POC system for quantitation of CD4 T cells in resource-limited settings given system throughput (80-100 cartridges/day), design simplicity, and ease-of-use. © 2015 International Clinical Cytometry Society.
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Affiliation(s)
- Monique Givens
- MBio Diagnostics Inc., 5603 Arapahoe Ave, Suite 1, Boulder, Colorado, 80303
| | - Amanda Weaver
- MBio Diagnostics Inc., 5603 Arapahoe Ave, Suite 1, Boulder, Colorado, 80303
| | - Sarah Bickman
- MBio Diagnostics Inc., 5603 Arapahoe Ave, Suite 1, Boulder, Colorado, 80303
| | - Cathy Logan
- Department of Microbiology, Universidade Eduardo Mondlane, Maputo, Mozambique, Africa
| | - Emilia V Noormahomed
- Department of Microbiology, Universidade Eduardo Mondlane, Maputo, Mozambique, Africa.,Division of Infectious Diseases, University of California, San Diego, 9500 Gilman Drive, MC 0711, San Diego, California, 92093
| | - Sam Patel
- Division of Infectious Diseases, University of California, San Diego, 9500 Gilman Drive, MC 0711, San Diego, California, 92093.,Department of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique, Africa
| | - Robert T Schooley
- Division of Infectious Diseases, University of California, San Diego, 9500 Gilman Drive, MC 0711, San Diego, California, 92093
| | - Constance A Benson
- Division of Infectious Diseases, University of California, San Diego, 9500 Gilman Drive, MC 0711, San Diego, California, 92093
| | - Michael J Lochhead
- MBio Diagnostics Inc., 5603 Arapahoe Ave, Suite 1, Boulder, Colorado, 80303
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Murphy C, Stack E, Krivelo S, McPartlin DA, Byrne B, Greef C, Lochhead MJ, Husar G, Devlin S, Elliott CT, O'Kennedy RJ. Detection of the cyanobacterial toxin, microcystin-LR, using a novel recombinant antibody-based optical-planar waveguide platform. Biosens Bioelectron 2014; 67:708-14. [PMID: 25459059 DOI: 10.1016/j.bios.2014.10.039] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/02/2014] [Accepted: 10/13/2014] [Indexed: 10/24/2022]
Abstract
Microcystins are a major group of cyanobacterial heptapeptide toxins found in freshwater and brackish environments. There is currently an urgent requirement for highly-sensitive, rapid and in-expensive detection methodologies for these toxins. A novel single chain fragment variable (scFv) fragment was generated and is the first known report of a recombinant anti-microcystin avian antibody. In a surface plasmon resonance-based immunoassay, the antibody fragment displayed cross-reactivity with seven microcystin congeners (microcystin-leucine-arginine (MC-LR) 100%, microcystin-tyrosine-arginine (MC-YR) 79.7%, microcystin-leucine-alanine (MC-LA) 74.8%, microcystin-leucine-phenylalanine (MC-LF) 67.5%, microcystin-leucine-tryptophan (MC-LW) 63.7%, microcystin-arginine-arginine (MC-RR) 60.1% and nodularin (Nod) 69.3%, % cross reactivity). Following directed molecular evolution of the parental clone the resultant affinity-enhanced antibody fragment was applied in an optimized fluorescence immunoassay on a planar waveguide detection system. This novel immuno-sensing format can detect free microcystin-LR with a functional limit of detection of 0.19 ng mL(-1)and a detection range of 0.21-5.9 ng mL(-1). The assay is highly reproducible (displaying percentage coefficients of variance below 8% for intra-day assays and below 11% for inter-day assays), utilizes an inexpensive cartridge system with low reagent volumes and can be completed in less than twenty minutes.
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Affiliation(s)
- Caroline Murphy
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland.
| | - Edwina Stack
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Svetlana Krivelo
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Daniel A McPartlin
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Barry Byrne
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | | | | | - Greg Husar
- MBio Diagnostics Inc., Boulder, CO, 80301, USA
| | - Shauna Devlin
- Institute for Global Food Security (IGFS), School of Biological Sciences, Queen's University, Malone Road, 18-30 Belfast, BT9 5BN, Northern Ireland, United Kingdom
| | - Christopher T Elliott
- Institute for Global Food Security (IGFS), School of Biological Sciences, Queen's University, Malone Road, 18-30 Belfast, BT9 5BN, Northern Ireland, United Kingdom
| | - Richard J O'Kennedy
- School of Biotechnology, National Centre for Sensor Research and Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
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9
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Devlin S, Meneely JP, Greer B, Greef C, Lochhead MJ, Elliott CT. Next generation planar waveguide detection of microcystins in freshwater and cyanobacterial extracts, utilising a novel lysis method for portable sample preparation and analysis. Anal Chim Acta 2013; 769:108-13. [PMID: 23498128 DOI: 10.1016/j.aca.2013.01.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/03/2012] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
Abstract
The study details the development of a fully validated, rapid and portable sensor based method for the on-site analysis of microcystins in freshwater samples. The process employs a novel lysis method for the mechanical lysis of cyanobacterial cells, with glass beads and a handheld frother in only 10 min. The assay utilises an innovative planar waveguide device that, via an evanescent wave excites fluorescent probes, for amplification of signal in a competitive immunoassay, using an anti-microcystin monoclonal with cross-reactivity against the most common, and toxic variants. Validation of the assay showed the limit of detection (LOD) to be 0.78 ng mL(-1) and the CCβ to be 1 ng mL(-1). Robustness of the assay was demonstrated by intra- and inter-assay testing. Intra-assay analysis had % C.V.s between 8 and 26% and recoveries between 73 and 101%, with inter-assay analysis demonstrating % C.V.s between 5 and 14% and recoveries between 78 and 91%. Comparison with LC-MS/MS showed a high correlation (R(2)=0.9954) between the calculated concentrations of 5 different Microcystis aeruginosa cultures for total microcystin content. Total microcystin content was ascertained by the individual measurement of free and cell-bound microcystins. Free microcystins can be measured to 1 ng mL(-1), and with a 10-fold concentration step in the intracellular microcystin protocol (which brings the sample within the range of the calibration curve), intracellular pools may be determined to 0.1 ng mL(-1). This allows the determination of microcystins at and below the World Health Organisation (WHO) guideline value of 1 μg L(-1). This sensor represents a major advancement in portable analysis capabilities and has the potential for numerous other applications.
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Affiliation(s)
- Shauna Devlin
- Institute for Global Food Security, School of Biological Sciences, Queen's University, Malone Road, 18-30 Belfast, BT9 5BN, Northern Ireland, United Kingdom.
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10
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Logan C, Givens M, Ives JT, Delaney M, Lochhead MJ, Schooley RT, Benson CA. Performance evaluation of the MBio Diagnostics point-of-care CD4 counter. J Immunol Methods 2012; 387:107-13. [PMID: 23063690 DOI: 10.1016/j.jim.2012.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/28/2012] [Accepted: 10/04/2012] [Indexed: 10/27/2022]
Abstract
The measurement of the absolute CD4 T-cell count is critical in the initial evaluation and staging of HIV-infected persons, yet access to this technology remains limited in many low resource settings where disease burden is highest. Here we evaluate the performance of a prototype point-of-care device (POC) to quantify CD4 T cells from MBio Diagnostics, Inc. Whole blood samples, both venous and capillary (finger stick), were collected from known HIV-infected participants at the University of California, San Diego Antiviral Research Center, and tested using the MBio system and conventional flow cytometry. A total of 94 venipuncture and 52 capillary samples were processed and statistical analyses included comparison to flow cytometry results. For the venipuncture samples, Bland-Altman analysis resulted in a mean bias of -10 cells/μL (-23 to +3 cells/μL, 95% CI), and limits of agreement (LOA) of -132 and +112 cells/μL. For the capillary samples, Bland-Altman resulted in a mean bias of -4 cells/μL (-31 to +23 cells/μL, 95% CL), and LOA of -195 and +186 cells/μL. For the San Diego study cohort, the prototype MBio system showed negligible quantitative bias relative to flow cytometry. Higher variability was observed in the capillary samples relative to venipuncture, but system precision for both capillary and venipuncture samples was good. There was also close agreement between results from the same participant when tested with two different systems, different operators and different locations. This preliminary evaluation suggests that the MBio CD4 device holds promise as a POC system for quantitation of CD4 T cells in limited-resource settings.
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Affiliation(s)
- Cathy Logan
- Division of Infectious Diseases, University of California, 9500 Gilman Drive, MC 0711, San Diego, CA 92093, USA.
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11
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Meneely JP, Campbell K, Greef C, Lochhead MJ, Elliott CT. Development and validation of an ultrasensitive fluorescence planar waveguide biosensor for the detection of paralytic shellfish toxins in marine algae. Biosens Bioelectron 2012; 41:691-7. [PMID: 23102433 DOI: 10.1016/j.bios.2012.09.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/12/2012] [Accepted: 09/22/2012] [Indexed: 11/30/2022]
Abstract
Marine dinoflagellates of the genera Alexandrium are well known producers of the potent neurotoxic paralytic shellfish toxins that can enter the food web and ultimately present a serious risk to public health in addition to causing huge economic losses. Direct coastal monitoring of Alexandrium spp. can provide early warning of potential shellfish contamination and risks to consumers and so a rapid, sensitive, portable and easy-to-use assay has been developed for this purpose using an innovative planar waveguide device. The disposable planar waveguide is comprised of a transparent substrate onto which an array of toxin-protein conjugates is deposited, assembled in a cartridge allowing the introduction of sample, and detection reagents. The competitive assay format uses a high affinity antibody to paralytic shellfish toxins with a detection signal generated via a fluorescently labelled secondary antibody. The waveguide cartridge is analysed by a simple reader device and results are displayed on a laptop computer. Assay speed has been optimised to enable measurement within 15 min. A rapid, portable sample preparation technique was developed for Alexandrium spp. in seawater to ensure analysis was completed within a short period of time. The assay was validated and the LOD and CCβ were determined as 12 pg/mL and 20 pg/mL respectively with an intra-assay CV of 11.3% at the CCβ and an average recovery of 106%. The highly innovative assay was proven to accurately detect toxin presence in algae sampled from the US and European waters at an unprecedented cell density of 10 cells/L.
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Affiliation(s)
- Julie P Meneely
- Institute of Agri-Food and Land Use, School of Biological Sciences, Queen's University, Malone Road, Belfast, BT9 5BN, United Kingdom.
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Harbers GM, Emoto K, Greef C, Metzger SW, Woodward HN, Mascali JJ, Grainger DW, Lochhead MJ. A functionalized poly(ethylene glycol)-based bioassay surface chemistry that facilitates bio-immobilization and inhibits non-specific protein, bacterial, and mammalian cell adhesion. Chem Mater 2008; 19:4405-4414. [PMID: 18815622 PMCID: PMC2546567 DOI: 10.1021/cm070509u] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This paper describes a new bioassay surface chemistry that effectively inhibits non-specific biomolecular and cell binding interactions, while providing a capacity for specific immobilization of desired biomolecules. Poly(ethylene glycol) (PEG) as the primary component in nonfouling film chemistry is well-established, but the multicomponent formulation described here is unique in that it (1) is applied in a single, reproducible, solution-based coating step; (2) can be applied to diverse substrate materials without the use of special primers; and (3) is readily functionalized to provide specific attachment chemistries. Surface analysis data are presented, detailing surface roughness, polymer film thickness, and film chemistry. Protein non-specific binding assays demonstrate significant inhibition of serum, fibrinogen, and lysozyme adsorption to coated glass, indium tin oxide, and tissue culture polystyrene dishes. Inhibition of S. aureus and K. pneumoniae microbial adhesion in a microfluidic flow cell, and inhibition of fibroblast cell adhesion from serum-based cell culture is shown. Effective functionalization of the coating is demonstrated by directing fibroblast adhesion to polymer surfaces activated with an RGD peptide. Batch-to-batch reproducibility data are included. The in situ cross-linked PEG-based coating chemistry is unique in its formulation, and its surface properties are attractive for a broad range of in vitro bioassay applications.
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Affiliation(s)
- Gregory M. Harbers
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872 USA
| | - Kazunori Emoto
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
| | - Charles Greef
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
| | - Steven W. Metzger
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
| | - Heather N. Woodward
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
| | - James J. Mascali
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
| | - David W. Grainger
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872 USA
| | - Michael J. Lochhead
- Accelr8 Technology Corporation, 7000 N. Broadway, Suite 3-307, Denver, CO 80221 USA
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Saldarriaga Fernández IC, van der Mei HC, Lochhead MJ, Grainger DW, Busscher HJ. The inhibition of the adhesion of clinically isolated bacterial strains on multi-component cross-linked poly(ethylene glycol)-based polymer coatings. Biomaterials 2007; 28:4105-12. [PMID: 17573108 DOI: 10.1016/j.biomaterials.2007.05.023] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Accepted: 05/25/2007] [Indexed: 11/24/2022]
Abstract
This study examined bacterial adhesion to a new multi-component cross-linked poly(ethylene glycol)-based polymer coating that can be applied by spin-coating or spraying onto diverse biomaterials. Adhesion of five clinically isolated bacterial strains involved in biomaterial-centered infections were studied in a parallel-plate flow chamber at different shear rates and after exposure of the coating to different physiological fluids. The new chemistry inhibits non-specific biomolecular and cell binding interactions. Relative to glass, the coating reduced adhesion of all strains used in this study by more than 80%, with the exception of Escherichia coli O2K2. Reductions in adhesion of Staphylococcus epidermidis 3,399 persisted beyond 168h exposure of the coatings to phosphate buffered saline or urine, but not after exposure to protein-rich fluids as saliva and blood plasma, despite evidence from X-ray photoelectron spectroscopy that the coating integrity was not affected by exposure to these fluids. We conclude that this new coating chemistry provides beneficial properties to prevent or hinder bacterial adhesion and colonization in applications where low protein-conditions prevail.
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Affiliation(s)
- Isabel C Saldarriaga Fernández
- Department of BioMedical Engineering, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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Touryan LA, Lochhead MJ, Marquardt BJ, Vogel V. Sequential switch of biomineral crystal morphology using trivalent ions. Nat Mater 2004; 3:239-243. [PMID: 15034562 DOI: 10.1038/nmat1096] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Accepted: 02/03/2004] [Indexed: 05/24/2023]
Abstract
Many biominerals are laminated such that crystal shape or habit changes from layer to layer thus yielding exquisitely designed composite materials with tightly controlled properties. Although lamination in biominerals is usually performed using peptides and proteins, here we introduce a new strategy by which sequential addition or depletion of inorganic trivalent ions in a supersaturated solution can be used to switch the surface morphology of calcium oxalate monohydrate (COM) back and forth, resulting in either the growth of flat crystalline sheets or of nanostructures oriented perpendicular to the surface. We propose that the occupation of a Ca(2+) site by Eu(3+) ion switches the orientation of the COM unit cell. The need to compensate the third charge forces coordination of Eu(3+) to an additional oxalate ion ((-)OOC-COO(-)) in an orientation that is not compatible with the initial unit cell. This mechanism of switching the orientation of the unit cell is unique, as it does not involve the use of expensive and thermally labile biomolecules. Suggestions of how to extend this strategy to engineer non-biological nanocomposites are given.
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Affiliation(s)
- Lara A Touryan
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
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Lochhead MJ, Touryan L, Vogel V. In Situ Analysis of Europium Calcium Oxalate Crystallization Using Luminescence Microspectroscopy. J Phys Chem B 1999. [DOI: 10.1021/jp984324+] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Letellier SR, Lochhead MJ, Campbell AA, Vogel V. Oriented growth of calcium oxalate monohydrate crystals beneath phospholipid monolayers. Biochim Biophys Acta 1998; 1380:31-45. [PMID: 9545525 DOI: 10.1016/s0304-4165(97)00121-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oriented calcium oxalate crystals have been grown beneath phospholipid monolayers at the air-solution interface from supersaturated calcium oxalate solutions. Mature calcium oxalate crystals grown beneath zwitterionic dipalmitoylphosphatidylcholine (DPPC) monolayers exhibit the characteristic morphology of calcium oxalate monohydrate (COM) crystals with the elongated (101) crystal face preferentially oriented parallel to the plane of the monolayer. Calcium oxalate crystals grown beneath negatively-charged dimyristoylphosphatidylserine (DMPS) monolayers also show a preferential orientation with respect to the monolayer; they do not, however, exhibit the characteristic COM morphology. Raman spectroscopy strongly suggests that the crystals grown beneath either DPPC or DMPS monolayers are the monohydrate phase of calcium oxalate; therefore, differences in crystal morphology are not due to differences in the crystalline phase. Dimyristoylphosphatidylethanolamine (DMPE), dimyristoylphosphatidic acid (DMPA), eicosanoic acid (C20), and eicosanol (C20-OH) monolayers have also been studied to help elucidate the mechanisms of interaction between the lipid monolayers and the calcium oxalate crystals. We discuss the roles of lattice matching, hydrogen bonding, stereochemistry and electrostatics on crystal orientation and morphology.
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Affiliation(s)
- S R Letellier
- Department of Bioengineering, University of Washington, Seattle, USA
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Lochhead MJ, Letellier SR, Vogel V. Assessing the Role of Interfacial Electrostatics in Oriented Mineral Nucleation at Charged Organic Monolayers. J Phys Chem B 1997. [DOI: 10.1021/jp972283w] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael J. Lochhead
- Department of Bioengineering, University of Washington, Seattle, Washington 98195
| | - Shelli R. Letellier
- Department of Bioengineering, University of Washington, Seattle, Washington 98195
| | - Viola Vogel
- Department of Bioengineering, University of Washington, Seattle, Washington 98195
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Lochhead MJ, Bray KL. High-pressure fluorescence line narrowing of Eu(III)-doped sodium disilicate glass. Phys Rev B Condens Matter 1995; 52:15763-15775. [PMID: 9980951 DOI: 10.1103/physrevb.52.15763] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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