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Yin F, Adhikari D, Peay M, Cortes D, Garada M, Shane Woolf M, Ma E, Lebarbenchon D, Mylott W, Dyszel M, Harriman S, Pinkas J. Development and validation of a hybrid immunoaffinity LC-MS/MS assay for quantitation of total antibody (TAb) from an antibody drug conjugate (ADC) PYX-201 in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1228:123844. [PMID: 37579604 DOI: 10.1016/j.jchromb.2023.123844] [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: 06/25/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/16/2023]
Abstract
A hybrid immunoaffinity LC-MS/MS assay was developed and validated for the quantitation of total antibody (TAb) from an antibody drug conjugate (ADC) PYX-201 in human plasma. PYX-201 was proteolyzed using trypsin, and a characteristic peptide fragment PYX-201 P1 with ten amino acids IPPTFGQGTK from the complementarity-determining regions (CDRs) was used as a surrogate for the quantitation of the TAb from PYX-201. Stable isotope labelled (SIL) peptide I(13C6, 15N)PPTFG(13C9, 15N)QGTK was used as the internal standard (IS). We performed chromatographic analysis using a Waters Acquity BEH Phenyl column (2.1 mm × 50 mm, 1.7 µm). Quantification of PYX-201 TAb was carried out on a Sciex triple quadrupole mass spectrometer API 6500 using multiple reaction monitoring (MRM) mode with positive electrospray ionization. To validate PYX-201 TAb, a concentration range of 0.0500 µg/mL to 20.0 µg/mL was used, yielding a correlation coefficient (r) of ≥ 0.9947. For intra-assay measurements, the percent relative error (%RE) ranged from -23.2% to 1.0%, with a coefficient of variation (%CV) of ≤ 14.2%. In terms of inter-assay measurements, the %RE was between -10.5% and -5.7%, with a %CV of ≤ 12.7%. The average recovery of the analyte was determined to be 81.4%, while the average recovery of the internal standard (IS) was 97.2%. Furthermore, PYX-201 TAb demonstrated stability in human plasma and human whole blood under various tested conditions. This assay has been successfully applied to human sample analysis to support a clinical study.
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Affiliation(s)
- Feng Yin
- Department of Nonclinical Research, Pyxis Oncology, Inc, 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Diana Adhikari
- Department of Nonclinical Research, Pyxis Oncology, Inc, 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Marlking Peay
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Diego Cortes
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Mohammed Garada
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - M Shane Woolf
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Eric Ma
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Diane Lebarbenchon
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - William Mylott
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Mike Dyszel
- Department of Project Management, Pyxis Oncology, Inc, 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Shawn Harriman
- Department of Nonclinical Research, Pyxis Oncology, Inc, 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA.
| | - Jan Pinkas
- Department of Nonclinical Research, Pyxis Oncology, Inc, 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA.
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Yin F, Adhikari D, Li Y, Turner D, Shane Woolf M, Lebarbenchon D, Ma E, Mylott W, Shaheen E, Harriman S, Pinkas J. A sensitive and rapid LC-MS/MS assay for quantitation of free payload Aur0101 from antibody drug conjugate (ADC) PYX-201 in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1226:123786. [PMID: 37352642 DOI: 10.1016/j.jchromb.2023.123786] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/25/2023]
Abstract
PYX-201 is an investigational antibody drug conjugate (ADC) with an engineered, fully human IgG1 antibody, a cleavable chemical linker, and a toxin (Aur0101) with an average drug-antibody ratio (DAR) of ∼ 4. A sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and fully validated to determine the presence in human plasma, of free payload Aur0101 from PYX-201 to assess drug safety and efficacy. Aur0101 and its deuterated internal standard (IS), Aur0101_d8, were extracted from 25 µL of human plasma using a solid liquid extraction (SLE) method. Chromatographic analysis was carried out on a Waters Acquity UPLC BEH C18 (2.1 mm × 50 mm, 1.7 µm, 130 A) column. Quantitation of free Aur0101 was conducted on a Sciex triple quadrupole mass spectrometer API 6500 + using multiple reaction monitoring (MRM) mode via positive electrospray ionization. The calibration curve was linear over the concentration range of 25.0 to 12,500 pg/mL with correlation coefficient, r2 ≥ 0.9988. The intra-assay %RE was between -4.3% to 14.3% with % CV was ≤ 6.2%. The inter-assay %RE was between -0.2% to 9.5% with % CV was ≤ 6.1%. The average analyte recovery was 89.7% and the average IS recovery was 88.7%. Aur0101 was found to be stable in human plasma and human whole blood under various tested conditions with and without the presence of PYX-201. To our knowledge, this is the first published fully validated assay for free, unconjugated Aur0101 in any matrix, from any species. This assay has been successfully applied to clinical sample analysis to support clinical studies.
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Affiliation(s)
- Feng Yin
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Diana Adhikari
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Yan Li
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Devan Turner
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - M Shane Woolf
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Diane Lebarbenchon
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Eric Ma
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - William Mylott
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services (a part of ThermoFisher Scientific), 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Elizabeth Shaheen
- Department of Project Management, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Shawn Harriman
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Jan Pinkas
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA.
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Woolf MS, Dignan LM, Karas SM, Lewis HM, Kim SN, Geise GM, DeMers HL, Hau D, Gates-Hollingsworth MA, AuCoin DP, Landers JP. Digital image analysis for biothreat detection via rapid centrifugal microfluidic orthogonal flow immunocapture. Anal Methods 2023; 15:1870-1880. [PMID: 36975002 DOI: 10.1039/d3ay00073g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We report clear proof-of-principle for centrifugally-driven, multiplexed, paper-based orthogonal flow sandwich-style immunocapture (cOFI) and colorimetric detection of Zaire Ebola virus-like particles. Capture antibodies are immobilized onto nanoporous nitrocellulose membranes that are then laminated into polymeric microfluidic discs to yield ready-to-use analytical devices. Fluid flow is controlled solely by rotational speed, obviating the need for complex pneumatic pumping systems, and providing more precise flow control than with the capillary-driven flow used in traditional lateral flow immunoassays (LFIs). Samples containing the antigen of interest and gold nanoparticle-labeled detection antibodies are pumped centrifugally through the embedded, prefunctionalized membrane where they are subsequently captured to generate a positive, colorimetric signal. When compared to the equivalent LFI counterparts, this cOFI approach generated immunochromatographic colorimetric responses that are objectively darker (saturation), more intense (grayscale), and less variable regarding total area of the color response. We also describe an image analysis approach that enables access to rich color data and area statistics without the need for a commercial 'strip reader' or custom-written image analysis algorithms. Instead, our analytical method exploits inexpensive equipment (e.g., smart phone, flatbed scanner, etc.) and freely available software (Fiji distribution of ImageJ) to permit characterization of immunochromatographic responses that includes multiple color metrics, offering insights beyond typical grayscale analysis. The findings reported here stand as clear proof-of-principle for the feasibility of disc-based, centrifugally driven orthogonal flow through a membrane with immunocapture (cOFI) and colorimetric readout of a sandwich-type immunoassay in less than 15 minutes. Once fully developed, this cOFI platform could render a faster, more accurate diagnosis, while processing multiple samples simul-taneously.
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Affiliation(s)
- M Shane Woolf
- Department of Chemistry, University of Virginia, USA
| | - Leah M Dignan
- Department of Chemistry, University of Virginia, USA
| | - Scott M Karas
- Department of Chemistry, University of Virginia, USA
| | | | - Sabrina N Kim
- Department of Chemistry, University of Virginia, USA
| | | | - Haley L DeMers
- Department of Microbiology and Immunology, University of Nevada, Reno, USA
| | - Derrick Hau
- Department of Microbiology and Immunology, University of Nevada, Reno, USA
| | | | - David P AuCoin
- Department of Microbiology and Immunology, University of Nevada, Reno, USA
| | - James P Landers
- Department of Chemistry, University of Virginia, USA
- Department of Mechanical Engineering, University of Virginia, USA
- Department of Pathology, University of Virginia, USA
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Yin F, Adhikari D, Sun M, Shane Woolf M, Ma E, Mylott W, Shaheen E, Harriman S, Pinkas J. Bioanalysis of an antibody drug conjugate (ADC) PYX-201 in human plasma using a hybrid immunoaffinity LC-MS/MS approach. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1223:123715. [PMID: 37094503 DOI: 10.1016/j.jchromb.2023.123715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/26/2023]
Abstract
PYX-201 is an anti-extra domain B splice variant of fibronectin (EDB + FN) antibody drug conjugate (ADC) composed of a fully human IgG1 antibody, a cleavable mcValCitPABC linker, and four Auristatin 0101 (Aur0101, PF-06380101) payload molecules. To better understand the pharmacokinetic (PK) profile of PYX-201 after it is administered to cancer patients, the development of a reliable bioanalytical assay to accurately and precisely quantitate PYX-201 in human plasma is required. In this manuscript, we present a hybrid immunoaffinity LC-MS/MS assay used to successfully analyze PYX-201 in human plasma. PYX-201 was enriched by MABSelect beads coated with protein A in human plasma samples. The bound proteins were subjected to "on-bead" proteolysis with papain to release the payload Aur0101. The stable isotope labelled internal standard (SIL-IS) Aur0101-d8 was added and the released Aur0101 was quantified as a surrogate for the total ADC concentration. The separation was performed on a UPLC C18 column coupled with tandem mass spectrometry. The LC-MS/MS assay was validated over the range 0.0250 to 25.0 µg/mL with excellent accuracy and precision. The overall accuracy (%RE) was between -3.8% and -0.1% and the inter-assay precision (%CV) was <5.8%. PYX-201 was found to be stable in human plasma for at least 24 h on ice, 15 days after being stored at -80 °C, as well as after five freeze/thaw cycles of being frozen at -25 °C or -80 °C and thawed on ice. The assay this paper reports on, has been successfully applied to human sample analysis to support clinical studies.
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Affiliation(s)
- Feng Yin
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Diana Adhikari
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Minghao Sun
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services, 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - M Shane Woolf
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services, 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Eric Ma
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services, 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - William Mylott
- Chromatographic Services - Research & Development, Biologics by LC-MS/MS, PPD Laboratory Services, 8700 Quioccasin Road, Henrico, VA 23229, USA
| | - Elizabeth Shaheen
- Department of Project Management, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA
| | - Shawn Harriman
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA.
| | - Jan Pinkas
- Department of Nonclinical Research, Pyxis Oncology, Inc., 321 Harrison Avenue, Suite 1, Boston, MA 02118, USA.
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Woolf MS, Cunha LL, Hadley KC, Moffett RP, Landers JP. Towards an affinity-free, centrifugal microfluidic system for rapid, automated forensic differential extraction. Anal Chim Acta 2023; 1249:340826. [PMID: 36868762 DOI: 10.1016/j.aca.2023.340826] [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: 10/05/2022] [Revised: 12/23/2022] [Accepted: 01/11/2023] [Indexed: 01/21/2023]
Abstract
Biological evidence originating from victims of sexual assault is often comprised of unbalanced cellular mixtures with significantly higher contributions from the victim's genetic material. Enrichment of the forensically-critical sperm fraction (SF) with single-source male DNA relies on differential extraction (DE), a manually-intensive process that is prone to contamination. Due to DNA losses from sequential washing steps, some existing DE methods often fail to generate sufficient sperm cell DNA recovery for perpetrator(s) identification. Here, we propose an enzymatic, 'swab-in' rotationally-driven microfluidic device to achieve complete, self-contained, on-disc automation of the forensic DE workflow. This 'swab-in' approach retains the sample within the microdevice, enabling lysis of sperm cells directly from the evidence cutting to improve sperm cell DNA yield. We demonstrate clear proof-of-concept of a centrifugal platform that provides for timed reagent release, temperature control for sequential enzymatic reactions, and enclosed fluidic fractionation that allows for objective evaluation of the DE process chain with a total processing time of ≤15 min. On-disc extraction of buccal or sperm swabs establishes compatibility of the prototype disc with: 1) an entirely enzymatic extraction method, and 2) distinct downstream analysis modalities, such as the PicoGreen® DNA assay for nucleic acid detection and the polymerase chain reaction (PCR).
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Affiliation(s)
- M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Larissa L Cunha
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
| | - Kevyn C Hadley
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Rachel P Moffett
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - James P Landers
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA; Department of Mechanical Engineering, University of Virginia, Charlottesville, VA, USA; Department of Pathology, University of Virginia, Charlottesville, VA, USA
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6
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Dignan LM, Woolf MS, Ross JA, Baehr C, Holstege CP, Pravetoni M, Landers JP. A Membrane-Modulated Centrifugal Microdevice for Enzyme-Linked Immunosorbent Assay-Based Detection of Illicit and Misused Drugs. Anal Chem 2021; 93:16213-16221. [PMID: 34807557 DOI: 10.1021/acs.analchem.1c04102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Increased opioid use and misuse have imposed large analytical demands across clinical and forensic sectors. Due to the absence of affordable, accurate, and simple on-site tests (e.g., point of interdiction and bedside), analysis is primarily conducted in centralized laboratories via time-consuming, labor-intensive methods. Many healthcare facilities do not have such analytical capabilities and must send samples to commercial laboratories, increasing turnaround time and care costs, as well as delaying public health warnings regarding the emergence of specific substances. Enzyme-linked immunosorbent assays (ELISAs) are used ubiquitously, despite lengthy workflows that require substantial manual intervention. Faster, reliable analytics are desperately needed to mitigate the mortality and morbidity associated with the current substance use epidemic. We describe one such alternative─a portable centrifugal microfluidic ELISA system that supplants repetitive pipetting with rotationally controlled fluidics. Embedded cellulosic membranes act as microvalves, permitting flow only when centrifugally generated hydraulic pressure exceeds their liquid entry pressure. These features enable stepwise reagent introduction, incubation, and removal simply by tuning rotational frequency. We demonstrate the success of this platform through sensitive, specific colorimetric detection of opiates, a subclass of opioids naturally derived from the opium poppy. Objective image analysis eliminated subjectivity in human color perception and permitted reliable detection of opiates in buffer and artificial urine at the ng/μL range. Opiates were clearly differentiated from other drug classes without interference from common adulterants known to cause false positive results in current colorimetric field tests. Eight samples were simultaneously analyzed in under 1 h, a marked reduction from the traditional multiday timeline. This approach could permit rapid, automatable ELISA-based drug detection outside of traditional laboratories by nontechnical personnel.
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Affiliation(s)
- Leah M Dignan
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Jennifer A Ross
- Department of Emergency Medicine, University of Virginia School of Medicine, Charlottesville, Virginia 22903, United States
| | - Carly Baehr
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, United States
| | - Christopher P Holstege
- Department of Emergency Medicine, University of Virginia School of Medicine, Charlottesville, Virginia 22903, United States
| | - Marco Pravetoni
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, United States
| | - James P Landers
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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7
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Dignan LM, Woolf MS, Tomley CJ, Nauman AQ, Landers JP. Multiplexed Centrifugal Microfluidic System for Dynamic Solid-Phase Purification of Polynucleic Acids Direct from Buccal Swabs. Anal Chem 2021; 93:7300-7309. [PMID: 33955733 DOI: 10.1021/acs.analchem.1c00842] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This report describes the development of a centrifugally controlled microfluidic dynamic solid-phase extraction (dSPE) platform to reliably obtain amplification-ready nucleic acids (NAs) directly from buccal swab cuttings. To our knowledge, this work represents the first centrifugal microdevice for comprehensive preparation of high-purity NAs from raw buccal swab samples. Direct-from-swab cellular lysis was integrated upstream of NA extraction, and automatable laser-controlled on-board microvalving strategies provided the strict spatiotemporal fluidic control required for practical point-of-need use. Solid-phase manipulation during extraction leveraged the application of a bidirectional rotating magnetic field to promote thorough interaction with the sample (e.g., NA capture). We illustrate the broad utility of this technology by establishing downstream compatibility of extracted nucleic acids with three noteworthy assays, namely, the polymerase chain reaction (PCR), reverse transcriptase PCR (RT-qPCR), and loop-mediated isothermal amplification (LAMP). The PCR-readiness of the extracted DNA was confirmed by generating short tandem repeat (STR) profiles following multiplexed amplification. With no changes to assay workflow, viral RNA was successfully extracted from contrived (spiked) SARS-CoV-2 swab samples, confirmed by RT-qPCR. Finally, we demonstrate the compatibility of the extracted DNA with LAMP-a technique well suited for point-of-need genetic analysis due to minimal hardware requirements and compatibility with colorimetric readout. We describe an automatable, portable microfluidic platform for the nucleic acid preparation device that could permit practical, in situ use by nontechnical personnel.
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Affiliation(s)
- Leah M Dignan
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Christopher J Tomley
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Aeren Q Nauman
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.,TeGrex Technologies, Charlottesville, Virginia 22903, United States
| | - James P Landers
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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Clark CP, Woolf MS, Karstens SL, Lewis HM, Nauman AQ, Landers JP. Closable Valves and Channels for Polymeric Microfluidic Devices. Micromachines (Basel) 2020; 11:E627. [PMID: 32605093 PMCID: PMC7407107 DOI: 10.3390/mi11070627] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/22/2020] [Accepted: 06/26/2020] [Indexed: 01/02/2023]
Abstract
This study explores three unique approaches for closing valves and channels within microfluidic systems, specifically multilayer, centrifugally driven polymeric devices. Precise control over the cessation of liquid movement is achieved through either the introduction of expanding polyurethane foam, the application of direct contact heating, or the redeposition of xerographic toner via chloroform solvation and evaporation. Each of these techniques modifies the substrate of the microdevice in a different way. All three are effective at closing a previously open fluidic pathway after a desired unit operation has taken place, i.e., sample metering, chemical reaction, or analytical measurement. Closing previously open valves and channels imparts stringent fluidic control-preventing backflow, maintaining pressurized chambers within the microdevice, and facilitating sample fractionation without cross-contamination. As such, a variety of microfluidic bioanalytical systems would benefit from the integration of these valving approaches.
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Affiliation(s)
- Charles P. Clark
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
| | - M. Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
| | - Sarah L. Karstens
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
| | - Hannah M. Lewis
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
| | - Aeren Q. Nauman
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
| | - James P. Landers
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA; (C.P.C.); (M.S.W.); (S.L.K.); (H.M.L.); (A.Q.N.)
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22903, USA
- Departments of Mechanical Engineering and Pathology, University of Virginia, Charlottesville, VA 22903, USA
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Woolf MS, Dignan LM, Lewis HM, Tomley CJ, Nauman AQ, Landers JP. Optically-controlled closable microvalves for polymeric centrifugal microfluidic devices. Lab Chip 2020; 20:1426-1440. [PMID: 32201873 DOI: 10.1039/c9lc01187k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Microvalving is a pivotal component in many microfluidic lab-on-a-chip platforms and micro-total analysis systems (μTAS). Effective valving is essential for the integration of multiple unit operations, such as, liquid transport, mixing, aliquoting, metering, washing, and fractionation. The ideal microfluidic system integrates numerous, sequential unit operations, provides precise spaciotemporal reagent release and flow control, and is amenable to rapid, low-cost fabrication and prototyping. Centrifugal microfluidics is an attractive approach that minimizes the need for supporting peripheral hardware. However, many of the microfluidic valving methods described in the literature suffer from operational limitations and fail when high rotational frequencies or pressure heads are required early in the analytical process. Current approaches to valve closure add unnecessary complexity to the microfluidic architecture, require the incorporation of additional materials such as wax, and entail extra fabrication steps or processes. Herein we report the characterization and optimization of a laser-actuated, closable valve method for polymeric microfluidic devices that ameliorates these shortcomings. Under typical operational conditions (rcf ≤605 ×g) a success rate >99% was observed, i.e. successful valve closures remained leak free through 605 ×g. Implementation of the laser-actuated closable valving system is demonstrated on an automated, centrifugally driven dynamic solid phase extraction (dSPE) device. Compatibility of this laser-actuated valve closure approach with commercially available polymerase chain reaction (PCR) assays is established by the generation of full 18-plex STR profiles from DNA purified via on-disc dSPE. This novel approach promises to simplify microscale valving, improve functionality by increasing the number of integrated unit operations, and allow for the automation of progressively complex biochemical assays.
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Wohlfahrt D, Woolf MS, Singh B. A survey of bacteria associated with various life stages of primary colonizers: Lucilia sericata and Phormia regina. Sci Justice 2019; 60:173-179. [PMID: 32111291 DOI: 10.1016/j.scijus.2019.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 10/28/2019] [Accepted: 11/03/2019] [Indexed: 10/25/2022]
Abstract
Blow flies are common primary colonizers of carrion, play an important role in the transfer of microbes between environments, and serve as a vector for many human pathogens. While some investigation has begun regarding the bacteria associated with different life stages of blow flies, a well replicated study is currently not available for the majority of blow flies. This study investigated bacteria associated with successive life stages of blow fly species Lucilia sericata and Phormia regina. A total of 38 samples were collected from four true replicates of L. sericata and P. regina. Variable region four (V4) of 16S ribosomal DNA (16S rDNA) was amplified and sequenced on MiSeq FGx sequencing platform using universal 16S rDNA primers and dual-index sequencing strategy. Bacterial communities associated with different life stages of L. sericata and P. regina didn't differ significantly from each other. In both blow fly species, Bacilli (e.g., Lactococcus) and Gammaproteobacteria (e.g., Providencia) constituted >95% of all bacterial classes across all life stages. At the genus level, Vagococcus and Leuconostoc were present at relatively high abundances in L. sericata whereas Yersinia and Proteus were present at comparatively high abundances in P. regina. Overall, information on bacterial structures associated with various life stages of blow flies can help scientists in better understanding or management of vector-borne pathogen dispersal and in increasing the accuracy of microbial evidence based postmortem interval (PMI) prediction models.
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Affiliation(s)
- Denise Wohlfahrt
- Integrative Life Sciences, Virginia Commonwealth University, Richmond, VA, United States; Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States.
| | - M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Baneshwar Singh
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States.
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Clark CP, Farmehini V, Spiers L, Woolf MS, Swami NS, Landers AJP. Real Time Electronic Feedback for Improved Acoustic Trapping of Micron-Scale Particles. Micromachines (Basel) 2019; 10:mi10070489. [PMID: 31330907 PMCID: PMC6681418 DOI: 10.3390/mi10070489] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 02/05/2023]
Abstract
Acoustic differential extraction has been previously reported as a viable alternative to the repetitive manual pipetting and centrifugation steps for isolating sperm cells from female epithelial cells in sexual assault sample evidence. However, the efficiency of sperm cell isolation can be compromised in samples containing an extremely large number of epithelial cells. When highly concentrated samples are lysed, changes to the physicochemical nature of the medium surrounding the cells impacts the acoustic frequency needed for optimal trapping. Previous work has demonstrated successful, automated adjustment of acoustic frequency to account for changes in temperature and buffer properties in various samples. Here we show that, during acoustic trapping, real-time monitoring of voltage measurements across the piezoelectric transducer correlates with sample-dependent changes in the medium. This is achieved with a wideband peak detector circuit, which identifies the resonant frequency with minimal disruption to the applied voltage. We further demonstrate that immediate, corresponding adjustments to acoustic trapping frequency provides retention of sperm cells from high epithelial cell-containing mock sexual assault samples.
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Affiliation(s)
- Charles P Clark
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA
| | - Vahid Farmehini
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22903, USA
| | - Liam Spiers
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA
| | - M Shane Woolf
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA
| | - Nathan S Swami
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22903, USA
| | - And James P Landers
- Department of Chemistry, University of Virginia, Charlottesville, VA 22903, USA.
- Departments of Mechanical Engineering and Pathology, University of Virginia, Charlottesville, VA 22903, USA.
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Woolf MS. Neurofibroma of the Rectum. Cal West Med 1938; 49:463-464. [PMID: 18744831 PMCID: PMC1659743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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13
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Woolf MS. Anorectal Fistulae - Advances in the Treatment. Cal West Med 1934; 40:238-242. [PMID: 18742826 PMCID: PMC1659078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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14
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Woolf MS. Proctology. Cal West Med 1931; 35:54. [PMID: 18741814 PMCID: PMC1657864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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15
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Woolf MS. A LIGHTED KELLY ANOSCOPE. Cal West Med 1929; 31:344. [PMID: 18741212 PMCID: PMC1657230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology: Hirschsprung's Disease. Cal West Med 1929; 30:362-363. [PMID: 18741043 PMCID: PMC1656234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. THE COMMONER SURGICAL DISEASES OF THE RECTUM, AND THEIR TREATMENT. Cal West Med 1928; 29:232-237. [PMID: 18740830 PMCID: PMC1656020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology: Chronic Ulcerrative Colitis. Cal West Med 1928; 29:110-111. [PMID: 18740781 PMCID: PMC1655836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology: Diverticulosis-Diverticulitis. Cal West Med 1928; 28:377-378. [PMID: 18740651 PMCID: PMC1655728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology: Tumors of the Rectum Exclusive of Carcinoma. Cal West Med 1927; 27:670-671. [PMID: 18740530 PMCID: PMC1655655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology: Anal Fistula-Bleeding from Rectum-Anesthesia in Rectal Operations. Cal West Med 1927; 26:814-815. [PMID: 18740387 PMCID: PMC1655525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. Proctology. Cal West Med 1927; 26:372. [PMID: 18740284 PMCID: PMC1655400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. PROCTOLOGY. Cal West Med 1927; 26:225-226. [PMID: 18740239 PMCID: PMC1655362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. CHRONIC ULCERATIVE COLITIS. Cal West Med 1926; 24:191-193. [PMID: 18739879 PMCID: PMC1654998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Woolf MS. CANCER OF THE RECTUM. Cal West Med 1924; 22:612-616. [PMID: 18739500 PMCID: PMC1654729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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