scholarly journals Development of NCOVID-19 Colloidal Gold Immunochromatographic Test Strip

2021 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Wenyi Liu ◽  
Zhaohua Li
Keyword(s):  
Colloidal Gold ◽  
Low Cost ◽  
Virus Detection ◽  
High Specificity ◽  
Accurate Method ◽  
Rapid Screening ◽  
Nucleic Acid Detection ◽  
Specificity And Sensitivity ◽  
Control Serum

<div><p>Purpose: To establish a fast, simple and accurate method and immunoassay test card for the detection of new coronavirus (nCOVID-19) antigen. Methods: In this study, colloidal gold immunochromatography technology was used to detect nCOVID-19 virus antigens through the sandwich method. At the same time, the preparation plan of colloidal gold was improved, and the application of rapid immune-diagnosis technology in other fields was developed. In this study, purified recombinant nCOVID-19 nucleocapsid protein is used as the antigen to prepare murine monoclonal antibodies. The BN02 antibody produced by the mouse is used as the detection antibody to couple with colloidal gold, forming a gold-labeled complex probe. BN9m1 is used as the coating antibody for the C-line, and ProA is used for the T-line. The polymerization of colloidal gold particles enables us to detect the new coronavirus antigen’s appearance. Thus an in vitro rapid detection kit for virus detection can be made. Results: The positive detection rate of the antigen quality control serum with this colloidal gold reagent was 100%. The specificity was 100%, and the sensitivity was 1ng/ml.  Conclusion: The nCOVID-19 antigen detection reagent (colloidal gold method) developed in this research has high specificity and sensitivity, and can be used in conjunction with nucleic acid detection. As a means of detecting nCOVID-19, it can achieve qualitative and rapid screening of samples with advantage such as accuracy, repeatability, and low cost.</p></div>

Selenium atom on phosphate enhances specificity and sensitivity of DNA polymerization and detection

2021 ◽  
Author(s):  
Guang-Cheng Luo ◽  
Jun Zhang ◽  
Mei Yang ◽  
Hongfei He ◽  
Zhen Huang
Keyword(s):  
Nucleic Acid ◽  
High Specificity ◽  
Nucleic Acid Detection ◽  
Selenium Atom ◽  
Dna Polymerization ◽  
Specificity And Sensitivity ◽  
Advanced Applications

DNA polymerization is of high specificity in vivo. However, its specificity is much lower in vitro, which limits the advanced applications of DNA polymerization in ultrasensitive nucleic acid detection. Herein...

Prospective Application of Aptamer-based Assays and Therapeutics in Bloodstream Infections

2020 ◽  
Vol 20 (10) ◽  
pp. 831-840
Author(s):  
Weibin Li
Keyword(s):  
Pathogenic Bacteria ◽  
Genetic Diagnosis ◽  
Bloodstream Infections ◽  
High Specificity ◽  
Peptide Sequence ◽  
High Morbidity ◽  
Specificity And Sensitivity ◽  
Prospective Application ◽  
Small Molecule Therapeutics

Sepsis is still a severe health problem worldwide with high morbidity and mortality. Blood bacterial culture remains the gold standard for the detection of pathogenic bacteria in bloodstream infections, but it is time-consuming, and both the sophisticated equipment and well-trained personnel are required. Immunoassays and genetic diagnosis are expensive and limited to specificity and sensitivity. Aptamers are single-stranded deoxyribonucleic acid (ssDNA) and ribonucleic acid (RNA) oligonucleotide or peptide sequence generated in vitro based on the binding affinity of aptamer-target by a process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX). By taking several advantages over monoclonal antibodies and other conventional small-molecule therapeutics, such as high specificity and affinity, negligible batch-to-batch variation, flexible modification and production, thermal stability, low immunogenicity and lack of toxicity, aptamers are presently becoming promising novel diagnostic and therapeutic agents. This review describes the prospective application of aptamerbased laboratory diagnostic assays and therapeutics for pathogenic bacteria and toxins in bloodstream infections.

scholarly journals RT-qPCR Assays for Rapid Detection of the N501Y, 69-70del, K417N, and E484K SARS-CoV-2 Mutations: A Screening Strategy to Identify Variants With Clinical Impact

2021 ◽  
Vol 11 ◽  
Author(s):  
Natali Vega-Magaña ◽  
Rocío Sánchez-Sánchez ◽  
Jorge Hernández-Bello ◽  
Alberto Antony Venancio-Landeros ◽  
Marcela Peña-Rodríguez ◽  
...  
Keyword(s):  
Biological Effects ◽  
Low Cost ◽  
Gene Mutations ◽  
High Specificity ◽  
Screening Strategy ◽  
Clinical Impact ◽  
Mexican Population ◽  
Rapid Screening ◽  
Clinical Samples ◽  
Reverse Transcription Pcr

BackgroundSeveral variants of the SARS-CoV-2 have been documented globally during the current COVID-19 pandemic. The N501Y, 69-70del, K417N, and E484K SARS-CoV-2 mutations have been documented among the most relevant due to their potential pathogenic biological effects. This study aimed to design, validate, and propose a fast real-time RT-qPCR assay to detect SARS-CoV-2 mutations with possible clinical and epidemiological relevance in the Mexican population.MethodsTargeting spike (S) gene mutations of SARS-CoV-2 (N501Y, 69-70del, K417N, and E484K), specific primers, and probes for three specific quantitative reverse transcription PCR (RT-qPCR) assays were designed, and validated using Sanger sequencing. These assays were applied in clinical samples of 1060 COVID-19 patients from Jalisco Mexico.ResultsIn silico analyzes showed high specificity of the three assays. Amplicons of samples were confirmed through sequencing. The screening of samples of COVID-19 patients allowed the identification of the E484K mutation in nine individuals and the identification of P.2 Brazilian variant in Mexico.ConclusionThis work provides low-cost RT-qPCR assays for rapid screening and molecular surveillance of mutations with potential clinical impact. This strategy allowed the detection of E484K mutation and P.2 variant for the first time in samples from the Mexican population.

scholarly journals Cytohistopathological Study of Salivary Gland Lesions in Bundelkhand Region, Uttar Pradesh, India

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Anita Omhare ◽  
Sanjeev Kumar Singh ◽  
Jitendra Singh Nigam ◽  
Ankit Sharma
Keyword(s):  
Salivary Gland ◽  
Low Cost ◽  
Uttar Pradesh ◽  
Diagnostic Technique ◽  
High Specificity ◽  
Turnaround Time ◽  
Malignant Tumours ◽  
Female Ratio ◽  
Specificity And Sensitivity ◽  
Benign Tumours

Background. FNAC is a useful method for evaluating suspicious salivary glands lesions due to its low cost, minimum morbidity, rapid turnaround time, high specificity, and sensitivity. Aim. To know the frequency of the salivary gland lesions and cytohistological correlation in the Jhansi region, Uttar Pradesh, India. Material and Methods. In present study 124 cases were included and cytohistological correlation was made in 86 cases only. FNA was performed by using a 23/24-gauge needle without local anaesthesia. Air dried and 95% ethyl alcohol fixed wet smears were stained with Giemsa stain and Papanicolaou stain, respectively. Paraffin embedded tissue sections were stained with Haematoxylin and Eosin. Results. Parotid gland was the most commonly involved salivary gland. The commonest age group was 20 to 29 years, 30 to 39 years, and 60 to 69 years for nonneoplastic lesions, benign tumours, and malignant tumours, respectively. The overall male to female ratio was 1.17 : 1. The diagnostic accuracy of FNAC was 100%, 93.3%, and 88.2% for nonneoplastic lesions, benign tumours, and malignant tumours, respectively. Conclusion. The high accuracy, sensitivity, and specificity of FNAC confirm that preoperative cytology is a useful, quick, reliable diagnostic technique for rapid diagnosis and suitable for developing countries.

scholarly journals Disposable silicon-based all-in-one micro-qPCR for rapid on-site detection of pathogens

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Estefania Nunez-Bajo ◽  
Alexander Silva Pinto Collins ◽  
Michael Kasimatis ◽  
Yasin Cotur ◽  
Tarek Asfour ◽  
...  
Keyword(s):  
Real Time ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Specificity ◽  
Rapid Screening ◽  
Quantitative Detection ◽  
The Novel ◽  
Novel Coronavirus ◽  
Silicon Based ◽  
Specific Sequences

AbstractRapid screening and low-cost diagnosis play a crucial role in choosing the correct course of intervention when dealing with highly infectious pathogens. This is especially important if the disease-causing agent has no effective treatment, such as the novel coronavirus SARS-CoV-2, and shows no or similar symptoms to other common infections. Here, we report a disposable silicon-based integrated Point-of-Need transducer (TriSilix) for real-time quantitative detection of pathogen-specific sequences of nucleic acids. TriSilix can be produced at wafer-scale in a standard laboratory (37 chips of 10 × 10 × 0.65 mm in size can be produced in 7 h, costing ~0.35 USD per device). We are able to quantitatively detect a 563 bp fragment of genomic DNA of Mycobacterium avium subspecies paratuberculosis through real-time PCR with a limit-of-detection of 20 fg, equivalent to a single bacterium, at the 35th cycle. Using TriSilix, we also detect the cDNA from SARS-CoV-2 (1 pg) with high specificity against SARS-CoV (2003).

scholarly journals Recent Progress in Nanomaterials Modified Electrochemical Biosensors for the Detection of MicroRNA

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1409
Author(s):  
Sze Shin Low ◽  
Daizong Ji ◽  
Wai Siong Chai ◽  
Jingjing Liu ◽  
Kuan Shiong Khoo ◽  
...  
Keyword(s):  
Electrochemical Biosensor ◽  
Sequence Similarity ◽  
Low Cost ◽  
High Specificity ◽  
Disease Diagnosis ◽  
Electrochemical Biosensors ◽  
High Sequence Similarity ◽  
Aberrant Expression ◽  
Specificity And Sensitivity ◽  
Different Types

MicroRNAs (miRNAs) are important non-coding, single-stranded RNAs possessing crucial regulating roles in human body. Therefore, miRNAs have received extensive attention from various disciplines as the aberrant expression of miRNAs are tightly related to different types of diseases. Furthermore, the exceptional stability of miRNAs has presented them as biomarker with high specificity and sensitivity. However, small size, high sequence similarity, low abundance of miRNAs impose difficulty in their detection. Hence, it is of utmost importance to develop accurate and sensitive method for miRNA biosensing. Electrochemical biosensors have been demonstrated as promising solution for miRNA detection as they are highly sensitive, facile, and low-cost with ease of miniaturization. The incorporation of nanomaterials to electrochemical biosensor offers excellent prospects for converting biological recognition events to electronic signal for the development of biosensing platform with desired sensing properties due to their unique properties. This review introduces the signal amplification strategies employed in miRNA electrochemical biosensor and presents the feasibility of different strategies. The recent advances in nanomaterial-based electrochemical biosensor for the detection of miRNA were also discussed and summarized based on different types of miRNAs, opening new approaches in biological analysis and early disease diagnosis. Lastly, the challenges and future prospects are discussed.

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

The Toxicity Testing of Cyanobacterial Toxins In Vivo and In Vitro by Mouse Bioassay: A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Hamed Ahari ◽  
Bahareh ‎ Nowruzi ◽  
Amir Ali Anvar ◽  
Samaneh Jafari Porzani
Keyword(s):  
Toxicity Testing ◽  
High Specificity ◽  
Immunological Methods ◽  
Water Bloom ◽  
Mouse Bioassay ◽  
Cell Extracts ◽  
Specificity And Sensitivity ◽  
Main Technique

: Different biological methods based on bioactivity are available to detect cyanotoxins, including neurotoxicity, immunological interactions, hepatotoxicity, cytotoxicity, and enzymatic activity. The mouse bioassay is the first test employed in laboratory cultures, cell extracts, and water bloom materials to detect toxins. It is also used as a traditional method to estimate the LD50. Concerning the ease of access and low cost, it is the most common method for this purpose. In this method, a sample is injected intraperitoneally into adult mice, and accordingly, they are assayed and monitored for about 24 hours for toxic symptoms. The toxin can be detected using this method from minutes to a few hours; its type, e.g., hepatotoxin, neurotoxin, etc., can also be determined. However, this method is nonspecific, fails to detect low amounts, and cannot distinguish between homologues. Although the mouse bioassay is gradually replaced with new chemical and immunological methods, it is still the main technique to detect the bioactivity and efficacy of cyanotoxins using LD50 determined based on the survival time of animals exposed to the toxin. In addition, some countries oppose animal use in toxicity studies. However, high cost, ethical considerations, low-sensitivity, non-specificity, and prolonged processes persuade researchers to employ chemical and functional analysis techniques. The qualitative and quantitative analyses, as well as high specificity and sensitivity, are among the advantages of cytotoxicity tests to investigate cyanotoxins. The present study aimed at reviewing the results obtained from in-vitro and in-vivo investigations of the mouse bioassay to detect cyanotoxins, including microcystins, cylindrospermopsin, saxitoxins, etc.

Fe-Based Single-Atom Nanozyme with Superior Peroxidase-Mimicking Activity for Enhanced Ultrasensitive Biosensing

2021 ◽  
Vol 21 (12) ◽  
pp. 6126-6134
Author(s):  
Lili Chi ◽  
Yuetong Zhang ◽  
Yusheng Hua ◽  
Qiqi Xu ◽  
Mingzhu Lv ◽  
...  
Keyword(s):  
Active Sites ◽  
Large Scale ◽  
Low Cost ◽  
Single Atom ◽  
Specificity And Sensitivity ◽  
Large Scale Preparation ◽  
Species Formation ◽  
Biomedical Diagnosis ◽  
Scale Preparation

Nanomaterials with intrinsic enzyme-mimicking characteristics, refered to as nanozymes, have become a hot research topic owing to their unique advantages of comparative low cost, high stability and large-scale preparation. Among them, Single-atom nanozymes (SAzymes), as novel nanozymes with abundant atomically dispersed active sites, have caused specific attention in the development of nanozymes for their remarkable catalytic activities, maximum atomic utilization and excellent selectivity, the homogeneous catalytic sites and clear catalytic mechanisms. Herein, a novel single-atom nanozyme based on Fe(III)-doped polydiaminopyridine nanofusiforms (Fe-PDAP SAzyme) was successfully proposed via facile oxidation polymerization strategy. With well-defined coordination structure and abundant Fe-Nx active sites similar to natural metalloproteases, the Fe-PDAP SAzyme exhibits superior peroxidase-like activity by efficiently decomposing H2O2 for hydroxyl radical (.OH) species formation. Based on their superior peroxidase-like activity, colorimetric biosensing of H2O2 and glucose in vitro was performed by using a typical 3,3,5,5-tetramethylbenzidine through a multienzyme biocatalytic cascade platform, exhibiting the superior specificity and sensitivity. This work not only provides a novel promising SAzyme-based biosensor but also paves an avenue for evaluating enzyme activity and broadens the application of other nanozyme-based biosensors in the fields of biomedical diagnosis.

Reflections of Fibrin Formation by In Vitro Testing

1979 ◽  
Author(s):  
G. Wilner
Keyword(s):  
Gel Permeation Chromatography ◽  
High Specificity ◽  
Structural Data ◽  
Specificity And Sensitivity ◽  
Immunological Tests ◽  
Great Specificity ◽  
Technical Simplicity ◽  
Derivatives Of

Measurement of enzymatically-modified fibrinogen, fibrin, or related proteolysie products represent a means whereby the action of several enzymes can be quantiated both in vitro and in vivo. Advances in physicochemical techniques and in immunology over the past decade permit translation of recently acquired primary structural data on fibrinogen and fibrin into sensitive and specific assays for detecting derivatives of these proteins in the circulation. Physicochemical techniques that have been used by various investigators include paracoagulation tests, affinity chromatography, gel permeation chromatography, and electrophoresis. The limitations in specificity and sensitivity of these techniques in detecting circulating fibrin(ogen) derivatives is offset by the technical simplicity of most of these procedures, and perhaps these techniques in combination may ultimately yield useful clinical tests. Immunological tests can, in theory, offer vastly improved specificity and sensitivity as compared with the above mentioned procedures. However, preparation of immune reagents of high specificity is both tedious and difficult, usually requiring multiple adsorbtion steps to harvest the desired antibody population. Our recent studies on the immunochemistry of human fibrinopeptide B suggest that by restricting the size of the immunizing antigen, one can readily obtain antibodies which are relatively. restricted as determined by isoelectric focusing experiments, and which also offer great specificity. The potential for developing new antibody and T cell orobes into workable assays for detecting circulating fibrin(ogen) derivatives remains to be exolored.

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