scholarly journals Recent Advances of Fluid Manipulation Technologies in Microfluidic Paper-Based Analytical Devices (μPADs) toward Multi-Step Assays

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 269 ◽  
Author(s):  
Taehoon H. Kim ◽  
Young Ki Hahn ◽  
Minseok S. Kim
Keyword(s):  
Developing Countries ◽  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
Medical Benefits ◽  
Diagnostic Cost ◽  
Polymerase Chain ◽  
Improved Performance ◽  
Fluid Manipulation

Microfluidic paper-based analytical devices (μPADs) have been suggested as alternatives for developing countries with suboptimal medical conditions because of their low diagnostic cost, high portability, and disposable characteristics. Recently, paper-based diagnostic devices enabling multi-step assays have been drawing attention, as they allow complicated tests, such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), which were previously only conducted in the laboratory, to be performed on-site. In addition, user convenience and price of paper-based diagnostic devices are other competitive points over other point-of-care testing (POCT) devices, which are more critical in developing countries. Fluid manipulation technologies in paper play a key role in realizing multi-step assays via μPADs, and the expansion of biochemical applications will provide developing countries with more medical benefits. Therefore, we herein aimed to investigate recent fluid manipulation technologies utilized in paper-based devices and to introduce various approaches adopting several principles to control fluids on papers. Fluid manipulation technologies are classified into passive and active methods. While passive valves are structurally simple and easy to fabricate, they are difficult to control in terms of flow at a specific spatiotemporal condition. On the contrary, active valves are more complicated and mostly require external systems, but they provide much freedom of fluid manipulation and programmable operation. Both technologies have been revolutionized in the way to compensate for their limitations, and their advances will lead to improved performance of μPADs, increasing the level of healthcare around the world.

scholarly journals Is Point-of-Care testing feasible and safe in care homes in England? An exploratory usability and accuracy evaluation of Point-of-Care Polymerase Chain Reaction test for SARS-COV-2

2020 ◽  
Author(s):  
Massimo Micocci ◽  
Adam L Gordon ◽  
Mikyung Kelly Seo ◽  
A. Joy Allen ◽  
Kerrie Davies ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Point Of Care ◽  
Care Home ◽  
Care Homes ◽  
Polymerase Chain Reaction Test ◽  
List Type ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Positive Agreement

AbstractIntroductionReliable rapid testing on COVID-19 is needed in care homes to reduce the risk of outbreaks and enable timely care. Point-of-care testing (POCT) in care homes could provide rapid actionable results. This study aimed to examine the usability and test performance of point of care polymerase chain reaction (PCR) for COVID-19 in care homes.MethodsPoint-of-care PCR for detection of SARS-COV2 was evaluated in a purposeful sample of four UK care homes. Test agreement with laboratory real-time PCR and usability and use errors were assessed.ResultsPoint of care and laboratory polymerase chain reaction (PCR) tests were performed on 278 participants. The point of care and laboratory tests returned uncertain results or errors for 17 and 5 specimens respectively. Agreement analysis was conducted on 256 specimens. 175 were from staff: 162 asymptomatic; 13 symptomatic. 69 were from residents: 59 asymptomatic; 10 symptomatic. Asymptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 98.7% negative agreement (95% CI: 96.2%-99.7%), with overall prevalence and bias-adjusted kappa (PABAK) of 0.965 (95% CI: 0.932 – 0.999). Symptomatic specimens showed 100% (95% CI: 2.5%-100%) positive agreement and 100% negative agreement (95% CI: 85.8%-100%), with overall PABAK of 1. No usability-related hazards emerged from this exploratory study.ConclusionApplications of point-of-care PCR testing in care homes can be considered with appropriate preparatory steps and safeguards. Agreement between POCT and laboratory PCR was good. Further diagnostic accuracy evaluations and in-service evaluation studies should be conducted, if the test is to be implemented more widely, to build greater certainty on this initial exploratory analysis.Key pointsPoint of care tests (POCT) in care homes are feasible and could increase testing capacity for the control of COVID-19 infection.The test of agreement between POCT and laboratory PCR for care home residents and the staff was good.Adoption of POCT in care homes can be considered with appropriate preparatory steps and safeguards in place.Repetitive errors and test malfunctioning can be mitigated with bespoke training for care home staff.Integrated care pathways should be investigated to test the high variability of the context of use.

scholarly journals Recent Advances in Novel Lateral Flow Technologies for Detection of COVID-19

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 295
Author(s):  
Wesley Wei-Wen Hsiao ◽  
Trong-Nghia Le ◽  
Dinh Minh Pham ◽  
Hui-Hsin Ko ◽  
Huan-Cheng Chang ◽  
...  
Keyword(s):  
Point Of Care ◽  
Lateral Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Laboratory Diagnostics ◽  
Rt Pcr ◽  
Point Of Care Testing ◽  
Specific Point ◽  
Recent Advances ◽  
Highly Sensitive ◽  
Polymerase Chain

The development of reliable and robust diagnostic tests is one of the most efficient methods to limit the spread of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, most laboratory diagnostics for COVID-19, such as enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR), are expensive, time-consuming, and require highly trained professional operators. On the other hand, the lateral flow immunoassay (LFIA) is a simpler, cheaper device that can be operated by unskilled personnel easily. Unfortunately, the current technique has some limitations, mainly inaccuracy in detection. This review article aims to highlight recent advances in novel lateral flow technologies for detecting SARS-CoV-2 as well as innovative approaches to achieve highly sensitive and specific point-of-care testing. Lastly, we discuss future perspectives on how smartphones and Artificial Intelligence (AI) can be integrated to revolutionize disease detection as well as disease control and surveillance.

scholarly journals Evaluation of commercially available immuno-magnetic agglutination and enzyme-linked immunosorbent assays for rapid point-of-care diagnostics of COVID-19

2020 ◽  
Author(s):  
Maria Engel Moeller ◽  
Jeppe Fock ◽  
Pearlyn Pah ◽  
Antia De La Campa Veras ◽  
Melanie Bade ◽  
...  
Keyword(s):  
Point Of Care ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Igg Antibodies ◽  
Chain Reaction ◽  
Point Of Care Test ◽  
Point Of Care Diagnostics ◽  
Polymerase Chain ◽  
Respiratory Coronavirus ◽  
Immunomagnetic Assay

Introduction: Coronavirus Disease 2019 (COVID-19) is caused by severe acute respiratory coronavirus-2 (SARS-CoV-2). Fast, accurate and simple blood-based assays for quantification of anti-SARS-CoV-2 antibodies are urgently needed to identify infected individuals and keep track of the spread of disease. Methods: The study included 35 plasma samples from 22 individuals with confirmed COVID-19 by real time reverse transcriptase polymerase chain reaction and 40 non COVID-19 plasma samples. Anti-SARS-CoV-2 IgM/IgA or IgG antibodies were detected by a microfluidic quantitative immunomagnetic assay (IMA)(ViroTrack Sero COVID IgM+IgA/IgG Ab, Blusense Diagnostics, Denmark) and by enzyme-linked immunosorbent assay ((ELISA) (EuroImmun Medizinische Labordiagnostika, Germany). Results: Of the 35 plasma samples from the COVID-19 patients, 29 (82.9%) were positive for IgA/IgM or IgG by IMA and 29 samples (82.9%) were positive by ELISA. Sensitivity for only one sample per patient was 68% for IgA+IgM and 73% IgG by IMA and 73% by ELISA. For samples collected 14 days after symptom onset, the sensitivity of both IMA and ELISA was around 90%. Specificity of the IMA reached 100% compared to 95% for ELISA IgA and 97.5% for ELISA IgG. Conclusion: IMA for COVID-19 is a rapid simple-to-use point of care test with sensitivity and specificity similar to a commercial ELISA.

scholarly journals Logistic advantage of two-step screening strategy for SARS-CoV-2 at airport quarantine

2021 ◽  
Author(s):  
Isao Yokota ◽  
Peter Y Shane ◽  
Takanori Teshima
Keyword(s):  
Point Of Care ◽  
High Accuracy ◽  
Screening Strategy ◽  
Nucleic Acid Amplification ◽  
Point Of Care Testing ◽  
Chain Reaction ◽  
False Negatives ◽  
Imported Cases ◽  
Polymerase Chain ◽  
Antigen Testing

SummaryBackgroundAirport quarantine is required to reduce the risk of entry of travelers infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, it is challenging for both high accuracy and rapid turn-around time to coexist in testing; polymerase chain reaction (PCR) is time-consuming with high accuracy, while antigen testing is rapid with less accuracy.Methods88,924 (93.2%) of 95,457 arrivals at three international airports in Japan were tested for SARS-CoV-2 using self-collected saliva by a screening strategy with initial chemiluminescent enzyme immunoassay (CLEIA) followed by confirmatory nucleic acid amplification tests (NAAT) only for intermediate range antigen concentrations.Results254 (0.27%) persons were found to be SARS-CoV-2 antigen positive (≥ 4.0 pg/mL) by CLEIA. NAAT was required for confirmatory testing in 513 (0.54%) persons with intermediate antigen concentrations (0.67-4.0 pg/mL) whereby the virus was detected in 34 (6.6%) persons. This two-step strategy dramatically reduced the utilization of NAAT to approximately one out of every 200 test subjects.Estimated performance of this strategy did not show significant increase in false negatives as compared to performing NAAT in all subjects. Further reduction in imported cases may be achieved by post-screening quarantine.ConclusionsPoint of care testing by quantitative CLEIA using self-collected saliva is less labor-intensive and yields results rapidly, thus suitable as an initial screening test. Reserving NAAT for CLEIA indeterminate cases may prevent compromising accuracy while significantly improving the logistics of administering mass-screening at large venues.

Utility of loop-mediated isothermal amplification as a point-of-care test in diagnosis of amoebic liver abscess

2021 ◽  
pp. 004947552110180
Author(s):  
Dipti Handa ◽  
Monica Gupta ◽  
Sarabmeet Singh Lehl ◽  
Amit Gupta ◽  
Ram Singh
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Liver Abscess ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Amoebic Liver Abscess ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Definitive diagnosis of amoebic liver abscess is challenging owing to the unavailability of sensitive commercial point-of-care molecular tests. The primary aim of our prospective diagnostic study was to compare available laboratory methods for the diagnosis of Entamoeba histolytica in clinical samples with loop-mediated isothermal amplification. We compared deoxyribonucleic acid (DNA) analysis methods, namely, loop-mediated isothermal amplification and reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) using pus, stool and blood samples from 200 patients with clinical and radiological diagnosis of amoebic liver abscess. Loop-mediated isothermal amplification had significantly higher sensitivity (88%) as compared to reverse transcriptase polymerase chain reaction (64%) and excellent specificity (100%).

scholarly journals Evaluation of Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcription Polymerase Chain Reaction for the Diagnosis of Foot-and-Mouth Disease

Intervirology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Salman Khan ◽  
Syed Asad Ali Shah ◽  
Syed Muhammad Jamal
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Genome ◽  
Foot And Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Kappa Value ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Level Of Agreement

<b><i>Background:</i></b> Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. <b><i>Methods:</i></b> A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. <b><i>Results:</i></b> S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (<i>p</i> = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. <b><i>Conclusions:</i></b> The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.

scholarly journals Occurrence of abortions induced by Neospora caninum in dairy cattle from Santa Catarina, southern Brazil

2017 ◽  
Vol 26 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Cesar Augusto Barbosa de Macedo ◽  
Madlaine Frigo Silveira Barbosa de Macedo ◽  
Ana Carolina Miura ◽  
Alessandra Taroda ◽  
Sergio Tosi Cardim ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
High Frequency ◽  
Neospora Caninum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Southern Brazil ◽  
Chain Reaction ◽  
Santa Catarina ◽  
Tissue Samples ◽  
Polymerase Chain

Abstract The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle.

scholarly journals A Self-Contained Portable Polymerase-Chain-Reaction System Integrated with Electromagnetic Mini-Actuators for Bi-Directional Fluid Transport

2011 ◽  
Vol 27 (3) ◽  
pp. 357-364
Author(s):  
B. T. Chia ◽  
S.-A. Yang ◽  
M.-Y. Cheng ◽  
C.-W. Lin ◽  
Y.-J. Yang
Keyword(s):  
Polymerase Chain Reaction ◽  
Fluid Transport ◽  
Point Of Care ◽  
Reaction System ◽  
Thermal Characteristics ◽  
Pcr Amplification ◽  
Chain Reaction ◽  
Rapid Temperature ◽  
Small Footprint ◽  
Polymerase Chain

ABSTRACTIn this paper, the development of a portable polymerase chain reaction (PCR) device is presented. Integrating electromagnetic mini-actuators for bi-directional fluid transport, the proposed device, whose dimension is 67mm × 66mm × 25mm, can be fully operated with a 5V DC voltage. The device consists of four major parts: A disposable channel chip in which PCR mixture is manipulated and reacted, a heater chip which generates different temperature zones for PCR reaction, a linear actuator array for pumping PCR mixture, and a circuit module for controlling and driving the system. The advantages of the device include the rapid temperature responses associated with continuous-flow-type PCR devices, as well as the programmable thermal cycling associated with chamber-type PCR devices. The thermal characteristics are measured and discussed. PCR amplification is successfully performed for the 122 bp segment of MCF-7/adr cell line. Due to its small footprint, this self-contained system potentially can be employed for point-of-care (POC) applications.

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