scholarly journals Development of a flow-free magnetic actuation platform for an automated microfluidic ELISA

RSC Advances ◽  
2019 ◽  
Vol 9 (15) ◽  
pp. 8159-8168 ◽  
Author(s):  
Chad Coarsey ◽  
Benjamin Coleman ◽  
Md Alamgir Kabir ◽  
Mazhar Sher ◽  
Waseem Asghar
Keyword(s):  
Point Of Care ◽  
Magnetic Actuation ◽  
Elisa Testing

A flow-free device is developed for automated and rapid ELISA testing at the point-of-care settings.

scholarly journals Antibody Responses in Cats Following Primary and Annual Vaccination against Feline Immunodeficiency Virus (FIV) with an Inactivated Whole-Virus Vaccine (Fel-O-Vax® FIV)

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 470
Author(s):  
Mark Westman ◽  
Dennis Yang ◽  
Jennifer Green ◽  
Jacqueline Norris ◽  
Richard Malik ◽  
...  
Keyword(s):  
Antibody Response ◽  
Virus Vaccine ◽  
Point Of Care ◽  
Primary Vaccination ◽  
Antibody Responses ◽  
Blood Samples ◽  
Study Results ◽  
Elisa Testing ◽  
Primary Antibody Response ◽  
Residual Blood

Although the antibody response induced by primary vaccination with Fel-O-Vax® FIV (three doses, 2–4 weeks apart) is well described, the antibody response induced by annual vaccination with Fel-O-Vax® FIV (single dose every 12 months after primary vaccination) and how it compares to the primary antibody response has not been studied. Residual blood samples from a primary FIV vaccination study (n = 11), and blood samples from cats given an annual FIV vaccination (n = 10), were utilized. Samples from all 21 cats were tested with a commercially available PCR assay (FIV RealPCRTM), an anti-p24 microsphere immunoassay (MIA), an anti-FIV transmembrane (TM; gp40) peptide ELISA, and a range of commercially available point-of-care (PoC) FIV antibody kits. PCR testing confirmed all 21 cats to be FIV-uninfected for the duration of this study. Results from MIA and ELISA testing showed that both vaccination regimes induced significant antibody responses against p24 and gp40, and both anti-p24 and anti-gp40 antibodies were variably present 12 months after FIV vaccination. The magnitude of the antibody response against both p24 and gp40 was significantly higher in the primary FIV vaccination group than in the annual FIV vaccination group. The differences in prime versus recall post-vaccinal antibody levels correlated with FIV PoC kit performance. Two FIV PoC kits that detect antibodies against gp40, namely Witness® and Anigen Rapid®, showed 100% specificity in cats recently administered an annual FIV vaccination, demonstrating that they can be used to accurately distinguish vaccination and infection in annually vaccinated cats. A third FIV PoC kit, SNAP® Combo, had 0% specificity in annually FIV-vaccinated cats, and should not be used in any cat with a possible history of FIV vaccination. This study outlines the antibody response to inactivated Fel-O-Vax® FIV whole-virus vaccine, and demonstrates how best to diagnose FIV infection in jurisdictions where FIV vaccination is practiced.

scholarly journals A Single-Bead-Based, Fully Integrated Microfluidic System for High-Throughput CD4+T Lymphocyte Enumeration

2017 ◽  
Vol 23 (2) ◽  
pp. 134-143 ◽  
Author(s):  
Xianbo Qiu ◽  
Junhui Zhang ◽  
Shisong Gong ◽  
Dong Wang ◽  
Shan Qiao ◽  
...  
Keyword(s):  
T Lymphocyte ◽  
High Throughput ◽  
Point Of Care ◽  
Low Cost ◽  
Ccd Camera ◽  
Microfluidic System ◽  
Magnetic Control ◽  
Magnetic Actuation ◽  
Fully Integrated ◽  
Single Bead

A single-bead-based, fully integrated microfluidic system has been developed for high-throughput CD4+T lymphocyte enumeration at point-of-care testing. Instead of directly counting CD4+T lymphocytes, CD4+T lymphocyte enumeration is achieved by quantitatively detecting CD4 antigen from the lysed blood sample with a functionalized polycarbonate single bead based on chemiluminescence. To implement the sandwiched chemiluminescence immunoassay with reduced nonspecific binding, a streamlined microfluidic chip with multiple reaction chambers is developed to allow each reaction step to be completed in an independent chamber where reagent is pre-stored. With simple magnetic control, the single bead with an embedded ferrous core can be consecutively transported between each of two adjacent chambers for different reactions. Meanwhile, enhanced mixing can be achieved by moving the single bead back and forth inside one chamber with magnetic actuation. High-throughput detection can be performed when a linear actuation stage is adopted to introduce synchronous magnetic control to multiple single beads in parallel microfluidic chips. A sensitive charge-coupled device (CCD) camera is adopted for high-throughput chemiluminescence detection from multiple single beads. Experimental results show that with the fully integrated microfluidic system, easy-to-operate, accurate, low-cost, immediate, and high-throughput CD4+T lymphocyte enumeration can be successfully achieved at resource-poor settings.

scholarly journals Clinical performance of two EUA-approved anti-COVID-19 IgG/IgM rapid lateral flow immunoassays using whole blood finger-sticks

2021 ◽  
Author(s):  
Christian Tagwerker ◽  
Irfan Baig ◽  
Eric Brunson ◽  
Kristine Mundo ◽  
Dava Dutra-Smith ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Whole Blood ◽  
Clinical Performance ◽  
Point Of Care ◽  
Cost Effective ◽  
Lateral Flow ◽  
Simultaneous Application ◽  
Igm Elisa ◽  
Elisa Testing ◽  
Finger Stick

Serological, or antibody, tests detect immunoglobulins produced by the hosts plasma B cells following exposure to foreign antigens. Venipuncture blood draws to collect human venous whole blood, plasma from anticoagulated blood (Li+ heparin, K2EDTA and sodium citrate), or serum are commonly utilized and require refrigerated temperatures during transport to the testing facility. Subsequent laboratory testing by enzyme-linked immunosorbent assays (ELISA) or chemiluminescence immunoassays (CLIA) can take an additional 2-5 hours. In the context of the COVID-19 pandemic, rapid diagnostic tests (RDT) to be used in point-of-care (POC) and remote settings have become essential during mandatory quarantine and isolation periods. RDTs allowed for more cost-effective testing using less collection materials with an immediate (5-10 minutes) test result. However, the majority of emerging RDTs receiving Emergency Use Authorization (EUA) approval by the Food and Drug Administration (FDA) for qualitative detection and differentiation of IgM and IgG antibodies to SARS-CoV-2 were only approved for use in human venous whole blood, plasma or serum. In this study we summarize performance characteristics of one RDT (COVID-19 IgG/IgM lateral flow immunoassay rapid cassette) to another by simultaneous application of whole blood finger-stick specimens (n = 32). The study was performed over 5 different days, with daily quality controls consisting of serum previously verified to be positive or negative by COVID-19 IgG/IgM ELISA testing.

scholarly journals Development of a Flow-Free Automated Colorimetric Detection Assay Integrated with Smartphone for Zika NS1

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 42 ◽  
Author(s):  
Md Alamgir Kabir ◽  
Hussein Zilouchian ◽  
Mazhar Sher ◽  
Waseem Asghar
Keyword(s):  
Zika Virus ◽  
Magnetic Beads ◽  
Nonstructural Protein ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Great Promise ◽  
Enzyme Linked Immunosorbent Assay ◽  
Magnetic Actuation ◽  
Superparamagnetic Beads ◽  
Nonstructural Protein 1

The Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitoes that can potentially cause microcephaly, Guillain–Barré Syndrome, and other birth defects. Effective vaccines for Zika have not yet been developed. There is a necessity to establish an easily deployable, high-throughput, low-cost, and disposable point-of-care (POC) diagnostic platform for ZIKV infections. We report here an automated magnetic actuation platform suitable for a POC microfluidic sandwich enzyme-linked immunosorbent assay (ELISA) using antibody-coated superparamagnetic beads. The smartphone integrated immunoassay is developed for colorimetric detection of ZIKV nonstructural protein 1 (NS1) antigen using disposable chips to accommodate the reactions inside the chip in microliter volumes. An in-house-built magnetic actuator platform automatically moves the magnetic beads through different aqueous phases. The assay requires a total of 9 min to automatically control the post-capture washing, horseradish peroxidase (HRP) conjugated secondary antibody probing, washing again, and, finally, color development. By measuring the saturation intensity of the developed color from the smartphone captured video, the presented assay provides high sensitivity with a detection limit of 62.5 ng/mL in whole plasma. These results advocate a great promise that the platform would be useful for the POC diagnosis of Zika virus infection in patients and can be used in resource-limited settings.

Cellphone-based hand-held microplate reader for point-of-care ELISA testing (Conference Presentation)

2016 ◽  
Author(s):  
Brandon Berg ◽  
Bingen Cortazar ◽  
Derek Tseng ◽  
Haydar Ozkan ◽  
Steve W. Feng ◽  
...  
Keyword(s):  
Point Of Care ◽  
Elisa Testing ◽  
Microplate Reader

“Aspirin - resistance”? A few critical considerations on definition, terminology, diagnosis, clinical value, natural course of atherosclerotic disease, and therapeutic consequences

VASA ◽  
2011 ◽  
Vol 40 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Berent ◽  
Sinzinger
Keyword(s):  
Platelet Function ◽  
Point Of Care ◽  
Aspirin Resistance ◽  
Point Of View ◽  
Evidence Based ◽  
Platelet Function Tests ◽  
Clinical Value ◽  
Vascular Events ◽  
Therapeutic Consequences ◽  
Function Tests

Based upon various platelet function tests and the fact that patients experience vascular events despite taking acetylsalicylic acid (ASA or aspirin), it has been suggested that patients may become resistant to the action of this pharmacological compound. However, the term “aspirin resistance” was created almost two decades ago but is still not defined. Platelet function tests are not standardized, providing conflicting information and cut-off values are arbitrarily set. Intertest comparison reveals low agreement. Even point of care tests have been introduced before appropriate validation. Inflammation may activate platelets, co-medication(s) may interfere significantly with aspirin action on platelets. Platelet function and Cox-inhibition are only some of the effects of aspirin on haemostatic regulation. One single test is not reliable to identify an altered response. Therefore, it may be more appropriate to speak about “treatment failure” to aspirin therapy than using the term “aspirin resistance”. There is no evidence based justification from either the laboratory or the clinical point of view for platelet function testing in patients taking aspirin as well as from an economic standpoint. Until evidence based data from controlled studies will be available the term “aspirin resistance” should not be further used. A more robust monitoring of factors resulting in cardiovascular events such as inflammation is recommended.

Cloud-Computing: eHealth aus der Wolke

2018 ◽  
Vol 23 (11) ◽  
pp. 38-41
Author(s):  
Sebastian Krolop ◽  
Florian Benthin ◽  
Constanze Knahl
Keyword(s):  
Cloud Computing ◽  
Point Of Care

Cloud-Computing gewinnt auch in Kliniken zunehmend an Bedeutung. Über das Internet bereitgestellte Lösungen verändern nicht nur Verwaltung und Logistik – im klinischen Bereich geht es zum Beispiel um die Nutzung elektronischer Patientenakten am Point-of-Care.

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