scholarly journals A low-cost fluorescence reader for in vitro transcription and nucleic acid detection with Cas13a

2019 ◽  
Author(s):  
Florian Katzmeier ◽  
Lukas Aufinger ◽  
Aurore Dupin ◽  
Jorge Quinteiro ◽  
Matthias Lenz ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Nucleic Acid Detection ◽  
Fluorescence Detector ◽  
Flat Detector ◽  
Low Resource Settings ◽  
Low Resource

AbstractPoint-of-care testing (POCT) in low-resource settings requires tools that can operate independent of typical laboratory infrastructure. Due to its favorable signal-to-background ratio, a wide variety of biomedical tests utilize fluorescence as a readout. However, fluorescence techniques often require expensive or complex instrumentation and can be difficult to adapt for POCT. To address this issue, we developed a pocket-sized fluorescence detector costing less than $15 that is easy to manufacture and can operate in low-resource settings. It is built from standard electronic components, including an LED and a light dependent resistor, filter foils and 3D printed parts, and reliably detected less than 10 nM fluorescein concentrations (with a lower limit of detection of ≈6.8 nM), which is sufficient to follow typical biochemical reactions used in POCT applications. All assays are conducted on filter paper, which allows for a flat detector architecture to improve signal collection. We validate the device by quantifying in vitro RNA transcription and also demonstrate sequence-specific detection of target RNAs in the nanomolar range using a Cas13a-based fluorescence assay. Cas13a is a RNA-guided, RNA-targeting CRISPR effector with promiscuous RNase activity upon recognition of its RNA target. Cas13a sensing is highly specific and adaptable and in combination with our detector represents a promising approach for nucleic acid POCT. Furthermore, our open-source device architecture could be a valuable educational tool that integrates hardware, software and biochemistry concepts.

scholarly journals A fully battery-powered inexpensive spectrophotometric system for high-sensitivity point-of-care analysis on a microfluidic chip

The Analyst ◽  
2016 ◽  
Vol 141 (12) ◽  
pp. 3898-3903 ◽  
Author(s):  
Maowei Dou ◽  
Juan Lopez ◽  
Misael Rios ◽  
Oscar Garcia ◽  
Chuan Xiao ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Power Supplies ◽  
Low Resource Settings ◽  
Low Resource ◽  
External Power

A low-cost b̲a̲ttery-powered s̲pectrophotometric s̲ystem (BASS) was developed for high-sensitivity point-of-care analysis in low-resource settings on a microfluidic chip without relying on external power supplies.

scholarly journals A low-cost fluorescence reader for in vitro transcription and nucleic acid detection with Cas13a

PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0220091 ◽  
Author(s):  
Florian Katzmeier ◽  
Lukas Aufinger ◽  
Aurore Dupin ◽  
Jorge Quintero ◽  
Matthias Lenz ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Low Cost ◽  
In Vitro Transcription ◽  
Nucleic Acid Detection

scholarly journals A low-cost smart system for electrophoresis-based nucleic acids detection at the visible spectrum

2020 ◽  
Author(s):  
Eduardo Nogueira Cunha ◽  
Maria Fernanda Bezerra de Souza ◽  
Daniel Carlos Ferreira Lanza ◽  
João Paulo Matos Santos Lima
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Low Cost ◽  
Visible Spectrum ◽  
Nucleic Acid Detection ◽  
Additional Risk Factor ◽  
Documentation System ◽  
Smart System ◽  
Wide Range ◽  
Image Capturing

ABSTRACTNucleic acid detection by electrophoresis is still a quick and accessible technique for many diagnosis methods, primarily at research laboratories or at the point of care units. Standard protocols detect DNA/RNA molecules through specific bound chemical dyes using a UV-transilluminator or UV-photo documentation system. However, the acquisition costs and availability of these devices, mainly the ones with photography and internet connection capabilities, can be prohibitive, especially in developing countries public health units. Also, ultraviolet radiation is a common additional risk factor to professionals that use electrophoresis-based nucleic acid detection. With that in mind, this work describes the development of a low-cost DNA/RNA detection smart system capable of obtaining qualitative and semi-quantitative data from gel analysis. The proposed device explores the visible light absorption range of commonly used DNA/RNA dyes using readily available parts, and simple manufacturing processes, such as light-emitting diodes (LEDs) and 3D impression. By applying IoT techniques, our system covers a wide range of color spectrum in order to detect bands from various commercially used dyes, using Bluetooth communication and a smartphone for hardware control, image capturing, and sharing. The project also enables process scalability and has low manufacturing and maintenance costs. The use of LEDs at the visible spectrum can achieve very reproducible images, providing a high potential for rapid and point-of-care diagnostics as well as applications in several fields such as healthcare, agriculture, and aquaculture.

Towards biomarker-based tests that can facilitate decisions about prevention and management of preeclampsia in low-resource settings

2016 ◽  
Vol 54 (1) ◽  
Author(s):  
Nathalie Acestor ◽  
Jane Goett ◽  
Arthur Lee ◽  
Tara M. Herrick ◽  
Susheela M. Engelbrecht ◽  
...  
Keyword(s):  
Health Care Providers ◽  
Clinical Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Care Providers ◽  
Low Resource Settings ◽  
Low Resource ◽  
High Resource ◽  
Rapid Assays ◽  
Urine Biomarkers

AbstractIn recent years, an increasing amount of literature is emerging on candidate urine and blood-based biomarkers associated with incidence and severity of preeclampsia (PE) in pregnant women. While enthusiasm on the usefulness of several of these markers in predicting PE is evolving, essentially all work so far has focused on the needs of high-resource settings and high-income countries, resulting primarily in multi-parameter laboratory assays based on proteomic and metabolomics analysis techniques. These highly complex methods, however, require laboratory capabilities that are rarely available or affordable in low-resource settings (LRS). The importance of quantifying maternal and perinatal risks and identifying which pregnancies can be safely prolonged is also much greater in LRS, where intensive care facilities that can rapidly respond to PE-related health threats for women and infants are limited. For these reasons, simple, low cost, sensitive, and specific point-of-care (POC) tests are needed that can be performed by antenatal health care providers in LRS and that can facilitate decisions about detection and management of PE. Our study aims to provide a comprehensive systematic review of current and emerging blood and urine biomarkers for PE, not only on the basis of their clinical performance, but also of their suitability to be used in LRS-compatible test formats, such as lateral flow and other variants of POC rapid assays.

scholarly journals Point-of-care device to diagnose and monitor neonatal jaundice in low-resource settings

2017 ◽  
Vol 114 (51) ◽  
pp. E10965-E10971 ◽  
Author(s):  
Pelham A. Keahey ◽  
Mathieu L. Simeral ◽  
Kristofer J. Schroder ◽  
Meaghan M. Bond ◽  
Prince J. Mtenthaonnga ◽  
...  
Keyword(s):  
Total Bilirubin ◽  
Point Of Care ◽  
Low Cost ◽  
Neurological Impairment ◽  
Reference Laboratory ◽  
Reference Standard ◽  
Low Resource Settings ◽  
Low Resource ◽  
Increased Risk ◽  
Pilot Clinical Study

Newborns are at increased risk of jaundice, a condition in which excess bilirubin accumulates in blood. Left untreated, jaundice can lead to neurological impairment and death. Jaundice resulting from unconjugated hyperbilirubinemia is easily treated with exposure to blue light, and phototherapy systems have been developed for low-resource settings; however, there are no appropriate solutions to diagnose and monitor jaundice in these settings. To address this need we present BiliSpec, a low-cost reader and disposable lateral flow card designed to measure the concentration of total bilirubin from several drops of blood at the point of care. We evaluated the performance of BiliSpec, using blood from normal volunteers spiked with varying amounts of bilirubin; results measured using BiliSpec correlated well with a reference laboratory bilirubinometer (r = 0.996). We then performed a pilot clinical study using BiliSpec to measure total bilirubin in neonates at risk for jaundice at Queen Elizabeth Central Hospital in Blantyre, Malawi. Concentrations measured using BiliSpec correlated well with those measured using a laboratory reference standard in 94 patient samples ranging from 1.1 mg/dL to 23.0 mg/dL in concentration (r = 0.973). The mean difference between bilirubin levels measured with BiliSpec and the reference standard was 0.3 mg/dL (95% CI: −1.7–2.2 mg/dL).

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals Siphon-Controlled Automation on a Lab-on-a-Disc Using Event-Triggered Dissolvable Film Valves

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 73
Author(s):  
Brian D. Henderson ◽  
David J. Kinahan ◽  
Jeanne Rio ◽  
Rohit Mishra ◽  
Damien King ◽  
...  
Keyword(s):  
Risk Factor ◽  
Limit Of Detection ◽  
C Reactive Protein ◽  
Cvd Risk ◽  
Low Resource Settings ◽  
Low Resource ◽  
Reactive Protein ◽  
Limit Of Quantitation ◽  
Chemiluminescent Immunoassay ◽  
Event Triggered

Within microfluidic technologies, the centrifugal microfluidic “Lab-on-a-Disc” (LoaD) platform offers great potential for use at the PoC and in low-resource settings due to its robustness and the ability to port and miniaturize ‘wet bench’ laboratory protocols. We present the combination of ‘event-triggered dissolvable film valves’ with a centrifugo-pneumatic siphon structure to enable control and timing, through changes in disc spin-speed, of the release and incubations of eight samples/reagents/wash buffers. Based on these microfluidic techniques, we integrated and automated a chemiluminescent immunoassay for detection of the CVD risk factor marker C-reactive protein displaying a limit of detection (LOD) of 44.87 ng mL−1 and limit of quantitation (LoQ) of 135.87 ng mL−1.

scholarly journals A glucose meter interface for point-of-care gene circuit-based diagnostics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evan Amalfitano ◽  
Margot Karlikow ◽  
Masoud Norouzi ◽  
Katariina Jaenes ◽  
Seray Cicek ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Synthetic Biology ◽  
Molecular Diagnostics ◽  
Point Of Care ◽  
Low Cost ◽  
Gene Circuit ◽  
Reporter Systems ◽  
Glucose Meter ◽  
Pandemic Response ◽  
Glucose Output

AbstractRecent advances in cell-free synthetic biology have given rise to gene circuit-based sensors with the potential to provide decentralized and low-cost molecular diagnostics. However, it remains a challenge to deliver this sensing capacity into the hands of users in a practical manner. Here, we leverage the glucose meter, one of the most widely available point-of-care sensing devices, to serve as a universal reader for these decentralized diagnostics. We describe a molecular translator that can convert the activation of conventional gene circuit-based sensors into a glucose output that can be read by off-the-shelf glucose meters. We show the development of new glucogenic reporter systems, multiplexed reporter outputs and detection of nucleic acid targets down to the low attomolar range. Using this glucose-meter interface, we demonstrate the detection of a small-molecule analyte; sample-to-result diagnostics for typhoid, paratyphoid A/B; and show the potential for pandemic response with nucleic acid sensors for SARS-CoV-2.

scholarly journals Demonstration of a Label-Free and Low-Cost Optical Cavity-Based Biosensor Using Streptavidin and C-Reactive Protein

Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Donggee Rho ◽  
Seunghyun Kim
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Optical Cavity ◽  
Sample Volume ◽  
Small Sample ◽  
Label Free ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Cavity Structure

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.

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