scholarly journals High-accuracy quantitative principle of a new compact digital PCR equipment: Lab On An Array

2021 ◽  
Vol 19 (3) ◽  
pp. e34
Author(s):  
Haeun Lee ◽  
Cherl-Joon Lee ◽  
Dong Hee Kim ◽  
Chun-Sung Cho ◽  
Wonseok Shin ◽  
...  
Keyword(s):  
Target Gene ◽  
Point Of Care ◽  
Region Of Interest ◽  
Digital Pcr ◽  
Absolute Quantification ◽  
Micro Electro Mechanical System ◽  
High Accuracy ◽  
Point Of Care Testing ◽  
Semiconductor Chip ◽  
Compact Size

Digital PCR (dPCR) is the third-generation PCR that enables real-time absolute quantification without reference materials. Recently, global diagnosis companies have developed new dPCR equipment. In line with the development, the Lab On An Array (LOAA) dPCR analyzer (Optolane) was launched last year. The LOAA dPCR is a semiconductor chip-based separation PCR type equipment. The LOAA dPCR includes Micro Electro Mechanical System that can be injected by partitioning the target gene into 56 to 20,000 wells. The amount of target gene per wells is digitized to 0 or 1 as the number of well gradually increases to 20,000 wells because its principle follows Poisson distribution, which allows the LOAA dPCR to perform precise absolute quantification. LOAA determined region of interest first prior to dPCR operation. To exclude invalid wells for the quantification, the LOAA dPCR has applied various filtering methods using brightness, slope, baseline, and noise filters. As the coronavirus disease 2019 has now spread around the world, needs for diagnostic equipment of point of care testing (POCT) are increasing. The LOAA dPCR is expected to be suitable for POCT diagnosis due to its compact size and high accuracy. Here, we describe the quantitative principle of the LOAA dPCR and suggest that it can be applied to various fields.

scholarly journals Comparative Use of Quantitative PCR (qPCR), Droplet Digital PCR (ddPCR), and Recombinase Polymerase Amplification (RPA) in the Detection of Shiga Toxin-Producing E. coli (STEC) in Environmental Samples

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3507
Author(s):  
Mark A. Ibekwe ◽  
Shelton E. Murinda ◽  
Stanley Park ◽  
Amarachukwu Obayiuwana ◽  
Marcia A. Murry ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Environmental Samples ◽  
Point Of Care ◽  
Foodborne Pathogen ◽  
Digital Pcr ◽  
Absolute Quantification ◽  
Droplet Digital Pcr ◽  
Recombinase Polymerase Amplification ◽  
High Rate ◽  
E Coli

E. coli O157:H7 is a foodborne pathogen that constitutes a global threat to human health. However, the quantification of this pathogen in food and environmental samples may be problematic at the low cell numbers commonly encountered in environmental samples. In this study, we used recombinase polymerase amplification (RPA) for the detection of E. coli O157:H7, real-time quantitative PCR (qPCR) for quantification, and droplet digital PCR (ddPCR) for absolute and accurate quantification of E. coli O157:H7 from spiked and environmental samples. Primer and probe sets were used for the detection of stx1 and stx2 using RPA. Genes encoding for stx1, stx2, eae, and rfbE were used to quantify E. coli O157:H7 in the water samples. Furthermore, duplex ddPCR assays were used to quantify the pathogens in these samples. Duplex assay set 1 used stx1 and rfbE genes, while assay set 2 used stx2 and eae genes. Droplet digital PCR was used for the absolute quantification of E. coli O15:H7 in comparison with qPCR for the spiked and environmental samples. The RPA results were compared to those from qPCR and ddPCR in order to assess the efficiency of the RPA compared with the PCR methods. The assays were further applied to the dairy lagoon effluent (DLE) and the high rate algae pond (HRAP) effluent, which were fed with diluted DLE. The RPA detected was <10 CFU/mL, while ddPCR showed quantification from 1 to 104 CFU/mL with a high reproducibility. In addition, quantification by qPCR was from 103 to 107 CFU/mL of the wastewater samples. Therefore, the RPA assay has potential as a point of care tool for the detection of E. coli O157:H7 from different environmental sources, followed by quantification of the target concentrations.

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.

scholarly journals Review of Integrated Optical Biosensors for Point-of-Care Applications

Biosensors ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 209
Author(s):  
Yung-Tsan Chen ◽  
Ya-Chu Lee ◽  
Yao-Hsuan Lai ◽  
Jin-Chun Lim ◽  
Nien-Tsu Huang ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Point Of Care ◽  
Future Perspective ◽  
Optical Biosensors ◽  
Microfluidic Channels ◽  
Point Of Care Testing ◽  
Electrical Control ◽  
Semiconductor Chip ◽  
Integrated Optical ◽  
Signal Readout

This article reviews optical biosensors and their integration with microfluidic channels. The integrated biosensors have the advantages of higher accuracy and sensitivity because they can simultaneously monitor two or more parameters. They can further incorporate many functionalities such as electrical control and signal readout monolithically in a single semiconductor chip, making them ideal candidates for point-of-care testing. In this article, we discuss the applications by specifically looking into point-of-care testing (POCT) using integrated optical sensors. The requirement and future perspective of integrated optical biosensors for POC is addressed.

Clinical Laboratory Medicine — Understanding Point-of-Care Testing and Provider-Performed Microscopy in Clinical Practice: Case-Based Curriculum for OBGYN and Pathology Residents

MedEdPORTAL ◽  
2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Veronica Lerner ◽  
Lauren Mcvoy ◽  
Maria Aguero-Rosenfeld ◽  
Amy Rapkiewicz ◽  
Abigail Winkel
Keyword(s):  
Clinical Practice ◽  
Clinical Laboratory ◽  
Point Of Care ◽  
Laboratory Medicine ◽  
Point Of Care Testing ◽  
Case Based

Magnetic Digital Microfluidics for Point-of-Care Testing: Where Are We Now?

2020 ◽  
Vol 27 ◽  
Author(s):  
Yi Zhang
Keyword(s):  
System Integration ◽  
Diagnostic Tests ◽  
Point Of Care ◽  
Digital Microfluidics ◽  
Controlled Environment ◽  
Point Of Care Testing ◽  
Microfluidic Platforms ◽  
Interface System ◽  
Technical Issues ◽  
Sample System

: Point-of-care (POC) testing decentralizes the diagnostic tests to the sites near the patient. Many POC tests rely microfluidic platforms for sample-to-answer analysis. Compared to other microfluidic systems, magnetic digital microfluidics demonstrate compelling advantages for POC diagnostics. In this review, we have examined the capability of magnetic digital microfluidics-based POC diagnostic platforms. More importantly, we have categorized POC settings into three classes based on “where is the point”, “who to care” and “how to test”, and evaluated the suitability of magnetic digital microfluidics in various POC settings. Furthermore, we have addressed other technical issues associated with POC testing such as controlled environment, sample-system interface, system integration and information connectivity. We hope this review would provide a guideline for the future development of magnetic digital microfluidics-based platforms for POC testing.

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