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1.
Adv Sci (Weinh) ; 11(32): e2403371, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38923850

RESUMO

Here, a separation-free and label-free portable aptasensor is developed for rapid and sensitive analysis of tumor-derived exosomes (TEXs). It integrated a parallel rolling circle amplification (RCA) reaction, selective binding of metal ions or small molecules to nucleic acid-specific conformations, and a low-cost, highly sensitive handheld fluorometer. Lung cancer, for example, is targeted with two typical biomarkers (mucin 1 and programmed cell death ligand 1 (PD-L1)) on its exosomes. The affinity of aptamers to the targets modulated the amount of RCA products (T-Hg2+-T and cytosine (C)-rich single-stranded DNA), which in turn affected the fluorescence intensity of quantum dots (QDs) and methylene blue (MB). The results revealed that the limit of detection (LOD) of the handheld fluorometer for cell-derived exosomes can be as low as 30 particles mL-1. Moreover, its specificity, sensitivity, and area under the curve (AUC) are 93% (14/15), 92% (23/25), and 0.956, as determined by the analysis of 40 clinical samples. Retesting 16 of these samples with the handheld fluorometer yielded strong concordance between the fluorometer results and those acquired from clinical computed tomography (CT) and pathology.


Assuntos
Exossomos , Neoplasias Pulmonares , Técnicas de Amplificação de Ácido Nucleico , Humanos , Exossomos/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Biópsia Líquida/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Aptâmeros de Nucleotídeos , Biomarcadores Tumorais/genética , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação
2.
Biosens Bioelectron ; 261: 116503, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38905856

RESUMO

Automation of liquid handling is indispensable to improve throughput and reproducibility in biochemical assays. However, the incorporation of automated systems into laboratory workflows is often hindered by the high cost and complexity associated with building robotic liquid handlers. Here, we report a 3D-printed liquid handler based on a fluidic manifold, thereby obviating the need for complex robotic mechanisms. The fluidic manifold, termed a dispensing and aspirating (DA) device, comprises parallelized multi-pipette structures connected by distribution and aspiration channels, enabling the precise supply and removal of reagents, respectively. Leveraging the versatility of 3D printing, the DA device can be custom-designed and printed to fit specific applications. As a proof-of-principle, we engineered a 3D-printed liquid handler dedicated for 3D digital rolling circle amplification (4DRCA), an advanced biochemical assay involving multiple sample preparation steps such as antibody incubation, cell fixation, nucleic acid amplification, probe hybridization, and extensive washing. We demonstrate the efficacy of the 3D-printed liquid handler to automate the preparation of clinical samples for the simultaneous, in situ analysis of oncogenic protein and transcript markers in B-cell acute lymphoblastic leukemia cells using 4DRCA. This approach provides an effective and accessible solution for liquid handling automation, offering high throughput and reproducibility in biochemical assays.


Assuntos
Técnicas Biossensoriais , Técnicas de Amplificação de Ácido Nucleico , Impressão Tridimensional , Humanos , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Desenho de Equipamento , Automação
3.
Adv Sci (Weinh) ; 11(23): e2310066, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38634211

RESUMO

Simple, sensitive, and accurate molecular diagnostics are critical for preventing rapid spread of infection and initiating early treatment of diseases. However, current molecular detection methods typically rely on extensive nucleic acid sample preparation and expensive instrumentation. Here, a simple, fully integrated, lab-in-a-magnetofluidic tube (LIAMT) platform is presented for "sample-to-result" molecular detection of virus. By leveraging magnetofluidic transport of micro/nano magnetic beads, the LIAMT device integrates viral lysis, nucleic acid extraction, isothermal amplification, and CRISPR detection within a single engineered microcentrifuge tube. To enable point-of-care molecular diagnostics, a palm-sized processor is developed for magnetofluidic separation, nucleic acid amplification, and visual fluorescence detection. The LIAMT platform is applied to detect SARS-CoV-2 and HIV viruses, achieving a detection sensitivity of 73.4 and 63.9 copies µL-1, respectively. Its clinical utility is further demonstrated by detecting SARS-CoV-2 and HIV in clinical samples. This simple, affordable, and portable LIAMT platform holds promise for rapid and sensitive molecular diagnostics of infectious diseases at the point-of-care.


Assuntos
COVID-19 , Dispositivos Lab-On-A-Chip , Técnicas de Amplificação de Ácido Nucleico , SARS-CoV-2 , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , COVID-19/diagnóstico , COVID-19/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/instrumentação , Desenho de Equipamento , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV/genética , HIV/isolamento & purificação
4.
Biosens Bioelectron ; 256: 116282, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38626615

RESUMO

Helicobacter pylori (H. pylori) infection correlates closely with gastric diseases such as gastritis, ulcers, and cancer, influencing more than half of the world's population. Establishing a rapid, precise, and automated platform for H. pylori diagnosis is an urgent clinical need and would significantly benefit therapeutic intervention. Recombinase polymerase amplification (RPA)-CRISPR recently emerged as a promising molecular diagnostic assay due to its rapid detection capability, high specificity, and mild reaction conditions. In this work, we adapted the RPA-CRISPR assay on a digital microfluidics (DMF) system for automated H. pylori detection and genotyping. The system can achieve multi-target parallel detection of H. pylori nucleotide conservative genes (ureB) and virulence genes (cagA and vacA) across different samples within 30 min, exhibiting a detection limit of 10 copies/rxn and no false positives. We further conducted tests on 80 clinical saliva samples and compared the results with those derived from real-time quantitative polymerase chain reaction, demonstrating 100% diagnostic sensitivity and specificity for the RPA-CRISPR/DMF method. By automating the assay process on a single chip, the DMF system can significantly reduce the usage of reagents and samples, minimize the cross-contamination effect, and shorten the reaction time, with the additional benefit of losing the chance of experiment failure/inconsistency due to manual operations. The DMF system together with the RPA-CRISPR assay can be used for early detection and genotyping of H. pylori with high sensitivity and specificity, and has the potential to become a universal molecular diagnostic platform.


Assuntos
Técnicas Biossensoriais , Técnicas de Genotipagem , Infecções por Helicobacter , Helicobacter pylori , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/microbiologia , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Técnicas de Genotipagem/instrumentação , Técnicas de Genotipagem/métodos , Genótipo , Proteínas de Bactérias/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Microfluídica/métodos , Antígenos de Bactérias/genética , Antígenos de Bactérias/análise , DNA Bacteriano/genética , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Recombinases/metabolismo
5.
Biomed Environ Sci ; 35(2): 133-140, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-35197178

RESUMO

OBJECTIVE: To establish a sensitive, simple and rapid detection method for African swine fever virus (ASFV) B646L gene. METHODS: A recombinase-aided amplification-lateral flow dipstick (RAA-LFD) assay was developed in this study. Recombinase-aided amplification (RAA) is used to amplify template DNA, and lateral flow dipstick (LFD) is used to interpret the results after the amplification is completed. The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid. In addition, 30 clinical samples were tested to evaluate the performance of the RAA assay. RESULTS: The RAA-LFD assay was completed within 15 min at 37 °C, including 10 min for nucleic acid amplification and 5 minutes for LFD reading results. The detection limit of this assay was found to be 200 copies per reaction. And there was no cross-reactivity with other swine viruses. CONCLUSION: A highly sensitive, specific, and simple RAA-LFD method was developed for the rapid detection of the ASFV.


Assuntos
Vírus da Febre Suína Africana/genética , Febre Suína Africana/radioterapia , Febre Suína Africana/virologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Febre Suína Africana/diagnóstico , Vírus da Febre Suína Africana/classificação , Vírus da Febre Suína Africana/isolamento & purificação , Animais , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Recombinases/química , Sensibilidade e Especificidade , Suínos , Proteínas Virais/genética
6.
Adv Sci (Weinh) ; 9(4): e2104084, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34913619

RESUMO

Herein, a programmable dual-catalyst hairpin assembly (DCHA) for realizing the synchronous recycle of two catalysts is developed, displaying high reaction rate and outstanding conversion efficiency beyond traditional nucleic acid signal amplifications (NASA). Once catalyst I interacts with the catalyst II, the DCHA can be triggered to realize the simultaneous recycle of catalysts I and II to keep the highly concentrated intermediate product duplex I-II instead of the steadily decreased one in typical NASA, which can accomplish in about only 16 min and achieves the outstanding conversion efficiency up to 4.54 × 108 , easily conquering the main predicaments of NASA: time-consuming and low-efficiency. As a proof of the concept, the proposed DCHA as a high-speed and hyper-efficiency DNA signal magnifier is successfully applied in the rapid and ultrasensitive detection of miRNA-21 in cancer cell lysates, which exploits the new generation of universal strategy for the applications in biosensing assay, clinic diagnose, and DNA nanobiotechnology.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , MicroRNAs/análise , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Células HeLa , Humanos , Limite de Detecção , Células MCF-7 , MicroRNAs/genética
7.
Nat Protoc ; 16(12): 5460-5483, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34716450

RESUMO

DNA hydrogels have unique properties, including sequence programmability, precise molecular recognition, stimuli-responsiveness, biocompatibility and biodegradability, that have enabled their use in diverse applications ranging from material science to biomedicine. Here, we describe a rolling circle amplification (RCA)-based synthesis of 3D DNA hydrogels with rationally programmed sequences and tunable physical, chemical and biological properties. RCA is a simple and highly efficient isothermal enzymatic amplification strategy to synthesize ultralong single-stranded DNA that benefits from mild reaction conditions, and stability and efficiency in complex biological environments. Other available methods for synthesis of DNA hydrogels include hybridization chain reactions, which need a large amount of hairpin strands to produce DNA chains, and PCR, which requires temperature cycling. In contrast, the RCA process is conducted at a constant temperature and requires a small amount of circular DNA template. In this protocol, the polymerase phi29 catalyzes the elongation and displacement of DNA chains to amplify DNA, which subsequently forms a 3D hydrogel network via various cross-linking strategies, including entanglement of DNA chains, multi-primed chain amplification, hybridization between DNA chains, and hybridization with functional moieties. We also describe how to use the protocol for isolation of bone marrow mesenchymal stem cells and cell delivery. The whole protocol takes ~2 d to complete, including hydrogel synthesis and applications in cell isolation and cell delivery.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , DNA Circular/química , DNA de Cadeia Simples/química , Hidrogéis/química , Técnicas de Amplificação de Ácido Nucleico/normas , Reação em Cadeia da Polimerase/métodos , Animais , Aptâmeros de Nucleotídeos/síntese química , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Separação Celular/métodos , Primers do DNA/síntese química , Primers do DNA/metabolismo , DNA Circular/genética , DNA Circular/metabolismo , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Hibridização de Ácido Nucleico/métodos , Proteínas Virais/genética , Proteínas Virais/metabolismo
8.
Biosens Bioelectron ; 178: 113001, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33493900

RESUMO

Amplification-based nucleic acid detection is widely employed in food safety, medical diagnosis and environment monitoring. However, conventional nucleic acid analysis has to be carried out in laboratories because of requiring expensive instruments and trained personnel. If people could do nucleic acid detection at home by themselves, the application of nucleic acid detection would be greatly accelerated. We herein reported a polypropylene (PP) bag-based method for convenient detection of nucleic acids in the oil-sealed space. The PP bag has three chambers which are responsible for lysis, washing and amplification/detection, respectively. After adding sample, nucleic acids are adsorbed on magnetic particles (MPs) and moved into these three chambers successively through immiscible oil channel by an external magnet. Combined with isothermal amplification, the PP bag can be incubated in a water bath or milk warmer and acted as a reaction tube. With highly specific CRISPR technology, Salmonella typhimurium (St) and SARS-CoV-2 can be visually detected in these PP bags within 1 h, indicating its potential household application. To further improve the reliability of nucleic acid testing at home, a logic decision method is introduced by detecting both target and endogenous reference gene. Positive/negative/invalid detection result can be obtained by chronologically adding the CRISPR reagents of target and endogenous reference gene. We anticipate that this PP bag can provide a novel toolkit for nucleic acid detection in people's daily life.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/virologia , Sistemas CRISPR-Cas , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Teste de Ácido Nucleico para COVID-19/instrumentação , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Microbiologia de Alimentos , Humanos , Magnetismo , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Polipropilenos , RNA Viral/genética , RNA Viral/isolamento & purificação , Salmonella typhimurium/genética , Salmonella typhimurium/isolamento & purificação , Autoteste
9.
Int J Mol Sci ; 21(22)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228234

RESUMO

Potato is an important staple food crop in both developed and developing countries. However, potato plants are susceptible to several economically important viruses that reduce yields by up to 50% and affect tuber quality. One of the major threats is corky ringspot, which is a tuber necrosis caused by tobacco rattle virus (TRV). The appearance of corky ringspot symptoms on tubers prior to commercialization results in ≈ 45% of the tubers being downgraded in quality and value, while ≈ 55% are declared unsaleable. To improve current disease management practices, we have developed simple diagnostic methods for the reliable detection of TRV without RNA purification, involving minimalized sample handling (mini), subsequent improved colorimetric loop-mediated isothermal amplification (LAMP), and final verification by lateral-flow dipstick (LFD) analysis. Having optimized the mini-LAMP-LFD approach for the sensitive and specific detection of TRV, we confirmed the reliability and robustness of this approach by the simultaneous detection of TRV and other harmful viruses in duplex LAMP reactions. Therefore, our new approach offers breeders, producers, and farmers an inexpensive and efficient new platform for disease management in potato breeding and cultivation.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Tipagem Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Plantas/virologia , Tubérculos/virologia , RNA Viral/genética , Solanum tuberosum/virologia , Colorimetria/instrumentação , Colorimetria/métodos , Humanos , Técnicas de Diagnóstico Molecular/instrumentação , Tipagem Molecular/instrumentação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Vírus de Plantas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Sci Rep ; 10(1): 4553, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165708

RESUMO

Breast cancer (BC) is a common cancer in women worldwide. Despite advances in treatment, up to 30% of women eventually relapse and die of metastatic breast cancer. Liquid biopsy analysis of circulating cell-free DNA fragments in the patients' blood can monitor clonality and evolving mutations as a surrogate for tumour biopsy. Next generation sequencing platforms and digital droplet PCR can be used to profile circulating tumour DNA from liquid biopsies; however, they are expensive and time consuming for clinical use. Here, we report a novel strategy with proof-of-concept data that supports the usage of loop-mediated isothermal amplification (LAMP) to detect PIK3CA c.3140 A > G (H1047R), a prevalent BC missense mutation that is attributed to BC tumour growth. Allele-specific primers were designed and optimized to detect the p.H1047R variant following the USS-sbLAMP method. The assay was developed with synthetic DNA templates and validated with DNA from two breast cancer cell-lines and two patient tumour tissue samples through a qPCR instrument and finally piloted on an ISFET enabled microchip. This work sets a foundation for BC mutational profiling on a Lab-on-Chip device, to help the early detection of patient relapse and to monitor efficacy of systemic therapies for personalised cancer patient management.


Assuntos
Neoplasias da Mama/diagnóstico , Classe I de Fosfatidilinositol 3-Quinases/genética , Técnicas de Diagnóstico Molecular/instrumentação , Mutação de Sentido Incorreto , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Primers do DNA/genética , Detecção Precoce de Câncer , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Biópsia Líquida , Células MCF-7 , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Projetos Piloto , Estudo de Prova de Conceito
11.
Adv Rheumatol ; 60: 42, 2020. tab
Artigo em Inglês | LILACS | ID: biblio-1130805

RESUMO

Abstract Background: Human herpesviruses (HHVs) are responsible for a significant number of clinical manifestations in systemic lupus erythematous (SLE) patients. The aim of this study was to determine the frequency of active HHV infections in SLE patients and correlating them with disease activity. Methods: Serum samples were collected from 71 SLE patients and their DNAs were extracted and analyzed to detect HHV-DNA viruses using the nucleic acid amplification technique. Results: Fifteen out of the 71 (21.1%) patients tested positive for the HHV-DNA virus. Of them, 11/15 HHV-DNA-positive patients (73.3%) had SLE activity index (SLEDAI - Systemic Lupus Erythematosus Disease Activity Index) ≥8 (p = 0.0001). Active HCMV infection was the mostly frequently observed infection, occurring in 6/15 patients (40%). The frequencies of other active viral infections were 22% for HSV-1, 16.7% for HHV-7, and 5.5% for HSV-2. Viral coinfection (two or more viruses detected in the same sample) occurred in three patients (16.7%). Active HHV infections in SLE patients are more frequent in those with active SLE (≥8), who is at high risk of HHV reactivation and HCMV disease. Conclusion: Viral surveillance is important to identify active HHV infections that can cause clinical symptoms and other complication in SLE patients.


Assuntos
Humanos , Infecções por Herpesviridae/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Lúpus Eritematoso Sistêmico/fisiopatologia , Reação em Cadeia da Polimerase/instrumentação , Coinfecção
12.
J Clin Virol ; 121: 104204, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31743836

RESUMO

BACKGROUND: Nucleic acid amplification tests (NAATs), such as PCR, are preferred for respiratory virus testing, due to superior diagnostic accuracy and faster turnaround time. Panther Fusion® Respiratory Assays (Fusion), which includes FluA/B/RSV (FFABR), Paraflu and AdV/hMPV/RV, offers a modular approach to syndromic testing on a fully automated platform while improving gene targets and expanding the test menu. OBJECTIVES AND STUDY DESIGN: We evaluated Fusion using 275 consecutive nasopharyngeal specimens previously used in an analysis of five PCRs, as well as 225 archived specimens. RESULTS: Of the combined 500 specimens, 134 were positive for influenza A (FluA), 54 for FluB, 65 for RSV, 64 for parainfluenza (PIV), 24 for adenovirus (AdV), 21 for humanmetapneumovirus (hMPV), and 40 for rhinovirus (RV) with Fusion. Of the positive samples Fusion correlated with historical results for all but one, despite multiple freeze-thaws cycles of this collection. Fusion was positive for an additional 33 samples, including 11 FluAs, 7 RSVs, 3 PIV3s, 3 AdV, 6 hMPV and 3 RVs. These samples were retested with corresponding Prodesse (Pro) assays using quadruple sample volume. This resolver test confirmed Fusion results for an additional 4 FluAs, 4 RSVs, 1 PIV3 and 3 AdVs. The sensitivity and specificity ranges of Fusion were 99-100% and 98-100%. Limit of detection (LOD) analyses were performed on a variety of Flu isolates. The LODs ranged from 2.69 to 2.99 log copies/ml and demonstrated superior LOD as compared to previously published data for some assays or to concurrent analyses with two new commercial tests.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Infecções Respiratórias/diagnóstico , Viroses/diagnóstico , Vírus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação Laboratorial , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Infecções Respiratórias/virologia , Sensibilidade e Especificidade , Viroses/virologia , Adulto Jovem
13.
Anal Chim Acta ; 1092: 49-56, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31708032

RESUMO

The studied challenge is the specific detection of low-abundant genomic variants that differ by a single nucleotide from the wild type. The combination of blocked recombinase polymerase amplification (RPA) and selective capture by probes immobilised on magnetic-core particles integrated into a flow system is presented. The sensing principle was demonstrated as the effective concentration-detection of the specific generated products was achieved. The analytical performance of resulting assay was successfully compared to PCR-based methods or array formats, providing faster effective detection of the selective products. As proof of concept, the single-nucleotide substitutions of the KRAS gene at codon 12 were studied in chip with parallel microchambers and permanent magnets. The blocked RPA products (generated at 37 °C) from tumour biopsies (extracted DNA 4 ng) provided a specific fluorescent bead-line that depends on the present mutation. The results agree with those reported by next-generation sequencing and provide new opportunities for in vitro diagnostic and personalised medicine.


Assuntos
Alelos , Biomarcadores Tumorais/análise , DNA/análise , Proteínas Proto-Oncogênicas p21(ras)/genética , Biomarcadores Tumorais/genética , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Corantes Fluorescentes/química , Genes ras , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção , Fenômenos Magnéticos , Microscopia de Fluorescência , Mutação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Hibridização de Ácido Nucleico , Polimorfismo de Nucleotídeo Único , Estudo de Prova de Conceito
14.
Nature ; 574(7777): 228-232, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31597972

RESUMO

Microfluidic systems can deliver portable point-of-care diagnostics without the need for external equipment or specialist operators, by integrating all reagents and manipulations required for a particular assay in one device1. A key approach is to deposit picogram quantities of dried reagents in microchannels with micrometre precision using specialized inkjet plotters2-5. This means that reagents can be stored for long periods of time and reconstituted spontaneously when adding a liquid sample. But it is challenging to carry out complex operations using multiple reagents, because shear flow enhances their dispersion and they tend to accumulate at moving liquid fronts, resulting in poor spatiotemporal control over the concentration profile of the reconstituted reagents6. One solution is to limit the rate of release of reagents into the liquid7-10. However, this requires the fine-tuning of different reagents, conditions and targeted operations, and cannot readily produce the complex, time-dependent multireagent concentration pulses required for sophisticated on-chip assays. Here we report and characterize a capillary flow phenomenon that we term self-coalescence, which is seen when a confined liquid with a stretched air-liquid interface is forced to 'zip' back onto itself in a microfluidic channel, thereby allowing reagent reconstitution with minimal dispersion. We provide a comprehensive framework that captures the physical underpinning of this effect. We also fabricate scalable, compact and passive microfluidic structures-'self-coalescence modules', or SCMs-that exploit and control this phenomenon in order to dissolve dried reagent deposits in aqueous solutions with precise spatiotemporal control. We show that SCMs can reconstitute multiple reagents so that they either undergo local reactions or are sequentially delivered in a flow of liquid. SCMs are easily fabricated in different materials, readily configured to enable different reagent manipulations, and readily combined with other microfluidic technologies, so should prove useful for assays, diagnostics, high-throughput screening and other technologies requiring efficient preparation and manipulation of small volumes of complex solutions.


Assuntos
Indicadores e Reagentes/análise , Microfluídica/métodos , Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/métodos , Testes Diagnósticos de Rotina , Ensaios Enzimáticos/instrumentação , Ensaios Enzimáticos/métodos , Fluorometria , Glucosefosfato Desidrogenase/análise , Glucosefosfato Desidrogenase/metabolismo , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/isolamento & purificação , Humanos , Microfluídica/instrumentação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos
15.
Anal Chem ; 91(19): 12428-12434, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31464423

RESUMO

Fusion genes, playing a causal role in human tumorigenesis and developments, are deemed as gold standard molecular biomarkers in cancer diagnosis, therapy, and prognosis. A rapid, robust, and sensitive method of detection of fusion genes for point-of-care (POC) diagnosis is urgently needed. Here, taking the advantages of the superior specificity of the ligation reaction and the highly amplified efficiency of isothermal exponential amplification with a pH indicator, we developed a colorimetric method for visual detection of fusion genes with high sensitivity and specificity by the naked eye. More importantly, we first found that fusion genes can be accurately quantified in a wide dynamic range (2 zmol to 2 fmol) by an open-source app with a smartphone-assisted RGB (red, green, and blue value) reading mode. The proposed method for Visual detection of Fusion genes by Ligation-triggered Isothermal Exponential Amplification is termed Vis-Fusion LIEXA. We have demonstrated that the Vis-Fusion LIEXA is a practical and reliable method for accurate quantitative detection of the fusion gene in a complex biological sample at zmol level in 40 min only with a smartphone, thereby providing a user-friendly and point-of-care testing (POCT) tool for molecular diagnostics.


Assuntos
Fusão Gênica , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Testes Imediatos , Smartphone , Estudos de Viabilidade , Células HeLa , Humanos , Células MCF-7
16.
Biosens Bioelectron ; 141: 111448, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31252258

RESUMO

Over the last decade, nucleic acid amplification tests (NAATs) including polymerase chain reaction (PCR) were an indispensable methodology for diagnosing cancers, viral and bacterial infections owing to their high sensitivity and specificity. Because the NAATs can recognize and discriminate even a few copies of nucleic acid (NA) and species-specific NA sequences, NAATs have become the gold standard in a wide range of applications. However, limitations of NAAT approaches have recently become more apparent by reason of their lengthy run time, large reaction volume, and complex protocol. To meet the current demands of clinicians and biomedical researchers, new NAATs have developed to achieve ultrafast sample-to-answer protocols for the point-of-care testing (POCT). In this review, ultrafast NA-POCT platforms are discussed, outlining their NA amplification principles as well as delineating recent advances in ultrafast NAAT applications. The main focus is to provide an overview of NA-POCT platforms in regard to sample preparation of NA, NA amplification, NA detection process, interpretation of the analysis, and evaluation of the platform design. Increasing importance will be given to innovative, ultrafast amplification methods and tools which incorporate artificial intelligence (AI)-associated data analysis processes and mobile-healthcare networks. The future prospects of NA POCT platforms are promising as they allow absolute quantitation of NA in individuals which is essential to precision medicine.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/análise , Animais , Inteligência Artificial/economia , Técnicas Biossensoriais/economia , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Desenho de Equipamento , Humanos , Técnicas de Amplificação de Ácido Nucleico/economia , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Ácidos Nucleicos/genética , Sistemas Automatizados de Assistência Junto ao Leito/economia , Reação em Cadeia da Polimerase/economia , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/métodos , Fatores de Tempo
17.
Anal Chem ; 91(13): 8036-8044, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31188565

RESUMO

Single cell RNA sequencing is a technology that provides the capability of analyzing the transcriptome of a single cell from a population. So far, single cell RNA sequencing has been focused mostly on human cells due to the larger starting amount of RNA template for subsequent amplification. One of the major challenges of applying single cell RNA sequencing to microbial cells is to amplify the femtograms of the RNA template to obtain sufficient material for downstream sequencing with minimal contamination. To achieve this goal, efforts have been focused on multiround RNA amplification, but would introduce additional contamination and bias. In this work, we for the first time coupled a microfluidic platform with multiple displacement amplification technology to perform single cell whole transcriptome amplification and sequencing of Porphyromonas somerae, a microbe of interest in endometrial cancer, as a proof-of-concept demonstration of using single cell RNA sequencing tool to unveil gene expression heterogeneity in single microbial cells. Our results show that the bacterial single-cell gene expression regulation is distinct across different cells, supporting widespread heterogeneity.


Assuntos
Perfilação da Expressão Gênica/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Porphyromonas/genética , Análise de Célula Única/instrumentação , Transcriptoma , Desenho de Equipamento , Regulação Bacteriana da Expressão Gênica , Técnicas de Amplificação de Ácido Nucleico/instrumentação
18.
Anal Chim Acta ; 1055: 115-125, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-30782362

RESUMO

Owing to the pivotal function in post transcriptional gene modification, miRNA biomarkers are playing crucial role in tracking and diagnosing various forms of tumors in a short time period. Hence, the need to develop simple, sensitive and specific detection of miRNAs for precise diagnosis arises. This current study is aimed to develop a detecting platform by combining rolling circle amplification with AuNps-based lateral flow strip (LFS-RCA) for simultaneous detection of miRNA 21 and miRNA let-7a. The current methodology is simple, sensitive, specific and selective for miRNA let-7a and miRNA 21 with the limits of detection (LOD) as low as 20 pM and 40 pM, respectively. In this technique, rolling circle amplification is playing an essential role in increasing sensitivity and reducing experimental cost. Moreover, the padlock probe with high specificity can immediately identify the simultaneous amplification of multiple miRNAs targets, which may contribute in saving sample volume and detection time. Hopefully, in future with further development, this developed technique can be chosen as a potential tool for detection of miRNAs in clinical diagnosis.


Assuntos
Limite de Detecção , MicroRNAs/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Sequência de Bases , Sondas de DNA/genética , Sondas de DNA/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Fatores de Tempo
19.
Lab Chip ; 19(6): 1035-1040, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30734822

RESUMO

Digital nucleic acid amplification and detection methods provide excellent sensitivity and specificity and allow absolute quantification of target nucleic acids. Isothermal methods such as digital loop-mediated isothermal amplification (digital LAMP) have potential for use in rapid disease diagnosis in low-resource settings due to their speed and lack of thermal cycling. We previously developed a self-digitization (SD) chip, a simple microfluidics device that automatically digitizes a sample into an array of nanoliter wells, for use in digital LAMP. In this work, we improve the SD chip design to increase sample loading efficiency, speed, and completeness, and test a range of well volumes and numbers. We demonstrate the diagnostic capability of this platform by applying it to quantifying human papillomavirus 18 gene.


Assuntos
DNA Viral/análise , Papillomavirus Humano 18/genética , Dispositivos Lab-On-A-Chip , Técnicas de Amplificação de Ácido Nucleico/métodos , DNA Viral/metabolismo , Humanos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Reprodutibilidade dos Testes
20.
J Clin Microbiol ; 57(4)2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30651389

RESUMO

The clinical performance of the Cobas CT/NG assay on the Cobas 6800/8800 systems (Cobas) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae was established in a multisite, prospective collection study using male and female urogenital specimens; supportive data from archived specimens were also included. The results obtained with the Cobas assay were compared with the patient infected status derived from a combination of U.S. Food and Drug Administration-approved nucleic acid amplification tests to determine the sensitivity and specificity of detection from each sample type. The sensitivity of Cobas for the detection of C. trachomatis in female specimens was 95.6% (95% confidence interval [CI], 92.4% to 97.4%) for urine; 98.6% (95% CI, 95.2% to 99.6%) and 99.2% (95% CI, 95.4% to 99.9%) for clinician- and self-collected vaginal swab specimens, respectively; 93.3% (95% CI, 89.6% to 95.7%) for endocervical swabs; and 92.5% (95% CI, 88.7% to 95.1%) for cervical swab samples in PreservCyt. The specificity for the detection of C. trachomatis was ≥98.8% for all female sample types. Sensitivity and specificity estimates of Cobas for the detection of C. trachomatis in male urine samples were 100% (96.8% to 100.0%) and 99.7% (95% CI, 99.2% to 99.9%), respectively. The sensitivity of Cobas for the detection of N. gonorrhoeae in female specimens was 94.8% (95% CI, 89.6% to 97.4%) for urine; 100.0% (95% CI, 87.9% to 100.0%) and 100.0% (95% CI, 87.9% to 100.0%) for clinician- and self-collected vaginal swab specimens, respectively; 97.0% (95% CI, 91.5% to 99.0%) for endocervical swabs; and 96.6% (95% CI, 90.6% to 98.8%) for cervical samples in PreservCyt; the specificity for all female sample types was >99.0%. The sensitivity and specificity of Cobas for detecting N. gonorrhoeae in male urine were 100.0% (95% CI, 95.8% to 100.0%) and 99.5% (95% CI, 98.8% to 99.8%), respectively. Fully automated assays help fill the clinical need for a sensitive, high-throughput screening tool to aid public health efforts to control C. trachomatis and N. gonorrhoeae infections.


Assuntos
Infecções por Chlamydia/urina , Chlamydia trachomatis/isolamento & purificação , Gonorreia/urina , Técnicas de Diagnóstico Molecular/normas , Neisseria gonorrhoeae/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Adolescente , Adulto , Idoso , Infecções Assintomáticas , Colo do Útero/microbiologia , Infecções por Chlamydia/diagnóstico , Técnicas de Laboratório Clínico , Feminino , Gonorreia/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Estudos Prospectivos , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Manejo de Espécimes , Sistema Urogenital/microbiologia , Esfregaço Vaginal , Adulto Jovem
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