An Immiscible-Phase Filtration Device for Isolation, Amplification, and Detection of Nucleic Acids for Clinical Diagnostics.

Clinical diagnostics of infectious diseases via nucleic acid amplification tests (NAATs) depend on a separate step of isolation of nucleic acids from cells/viruses embedded in complex biological matrices. The most recent example has been reverse transcription polymerase chain reaction (RT-PCR) for amplification and detection of SARS-CoV-2 RNA for COVID-19 diagnostics. Kits for RNA extraction and purification are commercially available; however, their integration with amplification systems is generally lacking, resulting in two separate steps, i.

Integrated microscale immiscible phase extraction and isothermal amplification for colorimetric detection of Neisseria gonorrhoeae.

Gonorrhea is the second most common sexually transmitted infection (STI) with around 87 million cases worldwide estimated in 2016 by the World Health Organization. With over half of the cases being asymptomatic, potential life-threatening complications and increasing numbers of drug-resistant strains, routine monitoring of prevalence and incidence of infections are key preventive measures. Whilst gold standard qPCR tests have excellent accuracy, they are neither affordable nor accessible in low-resource settings.

A sample-to-answer COVID-19 diagnostic device based on immiscible filtration and CRISPR-Cas12a-assisted detection.

In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic and disparities of vaccination coverage in low-and middle-income countries, it is vital to adopt a widespread testing and screening programme, combined with contact tracing, to monitor and effectively control the infection dispersion in areas where medical resources are limited. This work presents a lab-on-a-chip device, namely 'IFAST-LAMP-CRISPR', as an affordable, rapid and high-precision molecular diagnostic means for detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The herein proposed 'sample-to-answer' platform integrates RNA extraction, amplification and molecular detection with lateral flow readout in one device.

A lab-on-a-chip platform for integrated extraction and detection of SARS-CoV-2 RNA in resource-limited settings.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the unprecedented global pandemic of coronavirus disease-2019 (COVID-19). Efforts are needed to develop rapid and accurate diagnostic tools for extensive testing, allowing for effective containment of the infection via timely identification and isolation of SARS-CoV-2 carriers. Current gold standard nucleic acid tests require many separate steps that need trained personnel to operate specialist instrumentation in laboratory environments, hampering turnaround time and test accessibility, especially in low-resource settings.

Inertial focusing of microparticles, bacteria, and blood in serpentine glass channels.

Early detection of pathogenic microorganisms is pivotal to diagnosis and prevention of health and safety crises. Standard methods for pathogen detection often rely on lengthy culturing procedures, confirmed by biochemical assays, leading to >24 h for a diagnosis. The main challenge for pathogen detection is their low concentration within complex matrices.

Paper-based analytical devices for colorimetric detection of and and their antibiotic resistant strains in milk.

Animal derived milk which is an important part of human diet due to its high nutritional value not only supports humans but also presents a growth environment for pathogenic bacteria. Milk may become contaminated with bacteria through udder infections or through contact within the dairy farm environment. Infections are treated with antibiotics, with β-lactams most commonly used in veterinary medicine.

Rapid detection of Group B Streptococcus (GBS) from artificial urine samples based on IFAST and ATP bioluminescence assay: from development to practical challenges during protocol testing in Kenya.

We report the rapid detection (20 min) of Streptococcus agalactiae, Group B Streptococcus (GBS) employing on-chip magnetic isolation of GBS based on immiscible filtration assisted by surface tension (IFAST), followed by detection of the isolated GBS using an adenosine triphosphate (ATP) bioluminescence assay. Up to 80% GBS cells were isolated from spiked artificial urine samples with linear responses of bioluminescence signals from isolated cells at 2.3 × 102-9.

A Microfluidic Device for Rapid Screening of E. coli O157:H7 Based on IFAST and ATP Bioluminescence Assay for Water Analysis.

We present a simple microfluidic system for rapid screening of Escherichia coli (E. coli) O157:H7 employing the specificity of immunomagnetic separation (IMS) via immiscible filtration assisted by surface tension (IFAST), and the sensitivity of the subsequent adenosine triphosphate (ATP) assay by the bioluminescence luciferin/luciferase reaction. The developed device was capable of detecting E.

Multiplex sorting of foodborne pathogens by on-chip free-flow magnetophoresis.

This study reports multiplex sorting of Salmonella typhimurium and Escherichia coli 0157, from broth cultures and from pathogen-spiked skinned chicken breast enrichment broths by employing microfluidic free-flow magnetophoresis. Magnetic beads of different sizes and magnetite content, namely Dynabeads anti-salmonella and Hyglos-Streptavidin beads together with the corresponding pathogen-specific biotinylated recombinant phages, were utilised as affinity solid phases for the capture and concentration of viable S. typhimurium and E.

On-chip acoustophoretic isolation of microflora including S. typhimurium from raw chicken, beef and blood samples.

Pathogen analysis in food samples routinely involves lengthy growth-based pre-enrichment and selective enrichment of food matrices to increase the ratio of pathogen to background flora. Similarly, for blood culture analysis, pathogens must be isolated and enriched from a large excess of blood cells to allow further analysis. Conventional techniques of centrifugation and filtration are cumbersome, suffer from low sample throughput, are not readily amenable to automation and carry a risk of damaging biological samples.

Three-dimensional Mach-Zehnder interferometer in a microfluidic chip for spatially-resolved label-free detection.

Ultrafast laser writing of waveguides in glasses is a very flexible and simple method for direct on-chip integration of photonic devices. In this work we present a monolithic optofluidic device in fused silica providing label-free and spatially-resolved sensing in a microfluidic channel. A Mach-Zehnder interferometer is inscribed with the sensing arm orthogonally crossing the microfluidic channel and the reference arm passing over it.

A microreactor for the study of biotransformations by a cross-linked gamma-lactamase enzyme.

A (+)-gamma-lactamase was precipitated, cross-linked and the resulting solid crushed prior to immobilisation within a capillary column microreactor. The microreactor was subsequently used to study enzyme stability, activity, kinetics and substrate specificity. The thermophilic (+)-gamma-lactamase retained 100% of its initial activity at the assay temperature, 80 degrees C, for 6 h and retained 52% activity after 10 h, indicating the advantage of immobilisation.