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

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 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 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 Cellphone-Based Hand-Held Microplate Reader for Point-of-Care Testing of Enzyme-Linked Immunosorbent Assays

ACS Nano ◽  
2015 ◽  
Vol 9 (8) ◽  
pp. 7857-7866 ◽  
Author(s):  
Brandon Berg ◽  
Bingen Cortazar ◽  
Derek Tseng ◽  
Haydar Ozkan ◽  
Steve Feng ◽  
...  
Keyword(s):  
Point Of Care ◽  
Point Of Care Testing ◽  
Microplate Reader ◽  
Immunosorbent Assays

scholarly journals A Sensitive, Point-of-Care Detection of Small Molecules Based on a Portable Barometer: Aflatoxins In Agricultural Products

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 158
Author(s):  
Weiqi Zhang ◽  
Wenqin Wu ◽  
Chong Cai ◽  
Xiaofeng Hu ◽  
Hui Li ◽  
...  
Keyword(s):  
Food Safety ◽  
High Performance ◽  
Large Scale ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Detection Methods ◽  
Relative Standard ◽  
Microplate Reader ◽  
Assay Precision ◽  
Point Of Care Detection

Sensitive and point-of-care detection of small toxic molecules plays a key role in food safety. Aflatoxin, a typical small toxic molecule, can cause serious healthcare and economic issues, thereby promoting the development of sensitive and point-of-care detection. Although ELISA is one of the official detection methods, it cannot fill the gap between sensitivity and point-of-care application because it requires a large-scale microplate reader. To employ portable readers in food safety, Pt-catalysis has attracted increasing attention due to its portability and reliability. In this study, we developed a sensitive point-of-care aflatoxin detection (POCAD) method via a portable handheld barometer. We synthesized and characterized Au@PtNPs and Au@PtNPs conjugated with a second antibody (Au@PtNPs-IgG). A competitive immunoassay was established based on the homemade monoclonal antibody against aflatoxins. Au@PtNPs-IgG was used to catalyze the production of O2 from H2O2 in a sealed vessel. The pressure of O2 was then recorded by a handheld barometer. The aflatoxin concentration was inversely proportional to the pressure recorded via the barometer reading. After optimization, a limit of detection of 0.03 ng/mL and a linear range from 0.09 to 16.0 ng/mL were achieved. Recovery was recorded as 83.1%–112.0% along with satisfactory results regarding inner- and inter-assay precision (relative standard deviation, RSD < 6.4%). Little cross-reaction was observed. Additionally, the POCAD was validated by high-performance liquid chromatography (HPLC) by using peanut and corn samples. The portable POCAD exhibits strong potential for applications in the on-site detection of small toxic molecules to ensure food safety.

A Smartphone-based Microplate Reader for Point-of-Care ELISA Quantification

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

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