A PNA-Mediated Clamping PCR for Routine Detection of KRAS Mutations in Colorectal Carcinoma

2014 ◽  
Vol 29 (1) ◽  
pp. e55-e61 ◽  
Author(s):  
Francesca Messa ◽  
Federica Tonissi ◽  
Enrico Millo ◽  
Enrico Bracco ◽  
Silvana Ungari ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Low Cost ◽  
Screening Method ◽  
High Sensitivity ◽  
Kras Mutations ◽  
Laboratory Equipment ◽  
Highly Sensitive ◽  
Appropriate Therapy ◽  
Definition Of ◽  
Very High

The detection of somatic mutations in a tumor represents a valuable tool for tumor characterization and provides the clinicians with information for setting up the most appropriate therapy. KRAS mutations in codons 12 and 13 are important biomarkers routinely analyzed in the clinic for the management of anti-EGFR treatment in colorectal carcinoma (CRC). Here we report a sensitive and inexpensive assay for KRAS mutations based on a PNA-mediated PCR clamping. The assay displays very high sensitivity (0.7%) and specificity (96.7%) when compared to traditional sequencing (SS) and pyrosequencing (PS), two of the most commonly and routinely used methods employed today by diagnostic laboratories. Furthermore, the PNA assay requires only basic and low-cost laboratory equipment, in contrast with all the most recent PCR-based technologies, which are highly sensitive but also much more expensive. Finally, despite the PNA assay does not allow for the definition of specific mutations, it is the cheapest and easiest screening method to firstly stratify wild-type and mutated patients, information that is strictly necessary to clinicians for the management of CRC and anti-EGFR treatment.

Highly sensitive detection of Cr(vi) in groundwater by bimetallic NiFe nanoparticles

2017 ◽  
Vol 9 (6) ◽  
pp. 1031-1037 ◽  
Author(s):  
Jingtao Liu ◽  
Yu Ding ◽  
Lifei Ji ◽  
Xin Zhang ◽  
Fengchun Yang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Hexavalent Chromium ◽  
Low Cost ◽  
High Sensitivity ◽  
Sensitive Detection ◽  
Toxic Heavy Metal ◽  
Metal Pollutants ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Heavy Metal Pollutants

Hexavalent chromium (Cr(vi)) is one of the most toxic heavy metal pollutants in groundwater, and thus the detection of Cr(vi) with high sensitivity, accuracy, and simplicity and low cost is of great importance.

Highly sensitive, stable, and precise detection of dopamine with carbon dots/tyrosinase hybrid as fluorescent probe

RSC Advances ◽  
2014 ◽  
Vol 4 (87) ◽  
pp. 46437-46443 ◽  
Author(s):  
Hao Li ◽  
Juan Liu ◽  
Manman Yang ◽  
Weiqian Kong ◽  
Hui Huang ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Carbon Dots ◽  
Low Cost ◽  
High Sensitivity ◽  
Highly Sensitive

The carbon dots/tyrosinase hybrid as a low-cost fluorescent probe for the detection of dopamine exhibits high sensitivity, stability, and precision.

scholarly journals A Highly Sensitive Cell-Based TLR Reporter Platform for the Specific Detection of Bacterial TLR Ligands

2022 ◽  
Vol 12 ◽  
Author(s):  
Katharina Radakovics ◽  
Claire Battin ◽  
Judith Leitner ◽  
Sabine Geiselhart ◽  
Wolfgang Paster ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Ectopic Expression ◽  
High Sensitivity ◽  
High Specificity ◽  
Reporter System ◽  
Specificity And Sensitivity ◽  
Highly Sensitive ◽  
Definition Of ◽  
The Individual ◽  
Allergen Extracts

Toll-like receptors (TLRs) are primary pattern recognition receptors (PRRs), which recognize conserved microbial components. They play important roles in innate immunity but also in the initiation of adaptive immune responses. Impurities containing TLR ligands are a frequent problem in research but also for the production of therapeutics since TLR ligands can exert strong immunomodulatory properties even in minute amounts. Consequently, there is a need for sensitive tools to detect TLR ligands with high sensitivity and specificity. Here we describe the development of a platform based on a highly sensitive NF-κB::eGFP reporter Jurkat JE6-1 T cell line for the detection of TLR ligands. Ectopic expression of TLRs and their coreceptors and CRISPR/Cas9-mediated deletion of endogenously expressed TLRs was deployed to generate reporter cell lines selectively expressing functional human TLR2/1, TLR2/6, TLR4 or TLR5 complexes. Using well-defined agonists for the respective TLR complexes we could demonstrate high specificity and sensitivity of the individual reporter lines. The limit of detection for LPS was below 1 pg/mL and ligands for TLR2/1 (Pam3CSK4), TLR2/6 (Fsl-1) and TLR5 (flagellin) were detected at concentrations as low as 1.0 ng/mL, 0.2 ng/mL and 10 pg/mL, respectively. We showed that the JE6-1 TLR reporter cells have the utility to characterize different commercially available TLR ligands as well as more complex samples like bacterially expressed proteins or allergen extracts. Impurities in preparations of microbial compounds as well as the lack of specificity of detection systems can lead to erroneous results and currently there is no consensus regarding the involvement of TLRs in the recognition of several molecules with proposed immunostimulatory functions. This reporter system represents a highly suitable tool for the definition of structural requirements for agonists of distinct TLR complexes.

scholarly journals Highly Sensitive Non-Enzymatic Detection of Glucose at MWCNT-CuBTC Composite Electrode

2020 ◽  
Vol 10 (23) ◽  
pp. 8419
Author(s):  
Adriana Remes ◽  
Florica Manea ◽  
Sorina Motoc (m. Ilies) ◽  
Anamaria Baciu ◽  
Elisabeta I. Szerb ◽  
...  
Keyword(s):  
Composite Electrode ◽  
Glucose Sensor ◽  
Low Cost ◽  
Multiwall Carbon Nanotubes ◽  
Linear Sweep Voltammetry ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Roll Mill ◽  
Highly Sensitive ◽  
Enzymatic Detection

A novel electrochemical glucose sensor was developed, based on a multiwall carbon nanotubes (MWCNTs)-copper-1,3,5-benzenetricarboxylic acid (CuBTC)-epoxy composite electrode, named MWCNT-CuBTC. The electrode nanocomposite was prepared by a two-roll mill procedure and characterized morphostructurally by scanning electron microscopy (SEM). The CuBTC formed defined crystals with a wide size distribution, which were well dispersed and embedded in the MWCNTs. Its electrical conductivity was determined by four-point probe contact (DC) conductivity measurements. The electroactive surface area, determined using cyclic voltammetry (CV), was found to be 6.9 times higher than the geometrical one. The results of the electrochemical measurements using CV, linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), chronoamperometry (CA) and multiple pulse amperometry (MPA) showed that the MWCNT-CuBTC composite electrode displayed high electrocatalytic activity toward the oxidation of glucose and, as a consequence, very high sensitivity. The best sensitivity of 14,949 µAmM−1cm−1 was reached using MPA at the potential value of 0.6 V/SCE, which was much higher in comparison with other copper-based electrodes reported in the literature. The good analytical performance, low cost and simple preparation method make this novel electrode material promising for the development of an effective glucose sensor.

scholarly journals Highly sensitive control of transcriptional activity by factor heterodimerization

1994 ◽  
Vol 301 (1) ◽  
pp. 9-12 ◽  
Author(s):  
S Swillens ◽  
I Pirson
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
High Sensitivity ◽  
Biochemical Control ◽  
Cellular Functions ◽  
Effector Molecules ◽  
Highly Sensitive ◽  
New Type ◽  
Very High

Several molecular mechanisms have been proposed to explain highly sensitive controls of cellular functions by effector molecules. Here we study an equilibrium model describing the regulation of transcriptional activity through the heterodimerization of transcription factors. We demonstrate that this model involves a new type of biochemical control which accounts for a very high sensitivity.

Amplification-Free DNA Detection Using a Microtip-Sensor Decorated With LNA Probes for Rapid TB Screening

2011 ◽  
Author(s):  
Shinnosuke Inoue ◽  
Woon-Hong Yeo ◽  
Jong-Hoon Kim ◽  
Jae-Hyun Chung ◽  
Kyong-Hoon Lee ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Staphylococcus Epidermidis ◽  
Genomic Dna ◽  
Bacterial Culture ◽  
Low Cost ◽  
Surrogate Marker ◽  
High Sensitivity ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
Highly Sensitive

Tuberculosis (TB) is an epidemic affecting one-third of the world’s population, mostly in developing and low-resource settings. People having active pulmonary TB are considered highly infectious; therefore, it is critical to identify and treat these patients rapidly before spreading to others. However, the most reliable TB diagnostic methods of bacterial culture or nucleic acid amplification are time-consuming and expensive. The challenge of TB diagnosis lies in highly sensitive and specific screening with low cost. Here, we present an LNA-modified microtip-sensor, which is capable of selectively detecting low-abundance DNA from bacteria. When genomic DNA of Bacillus Calmette-Gue´rin (BCG, a surrogate marker of Mycobacterium bovis), and genomic DNA of Staphylococcus epidermidis (S. epi) are used, the microtip-sensor yields the detection limit of 1,000 copies/mL within 20 minutes. The high sensitivity and specificity approaching nucleic acid amplification methods can potentially overcome the current challenges for rapid TB screening.

A QCM Immunosensor for Rapid Determination of Ractopamine in Food Based on Enzyme-AuNPs for Signal Amplification and Magnetic β-Cyclodextrins for Extraction

2015 ◽  
Vol 738-739 ◽  
pp. 56-60
Author(s):  
Shu Xian Chen ◽  
Jing Liu ◽  
Dao Dong Pan ◽  
Ning Gan
Keyword(s):  
Signal Amplification ◽  
Rapid Determination ◽  
Screening Method ◽  
High Sensitivity ◽  
The Novel ◽  
Highly Sensitive ◽  
Reliable Quantification ◽  
Highly Sensitive Detection ◽  
Amplification Strategy

An enzyme amplified immunosensor for highly sensitive detection of Ractopamine (RAC) in foodstuff was developed based on quartz crystal microbalance (QCM). The high sensitivity was achieved by enzyme-AuNPs signal amplification strategy and magnetic β-cyclodextrins (β-CD) enrichment capacity. The novel QCM immunosensor which combines with the advantages of high selectivity of immunoassays and the high sensitivity of QCM has been developed for the determination of trace residues of RAC in food production. Under optimum conditions, the differences in the frequencies (∆f) of the QCM were proportional to the concentration of RAC over the range from 0.01 to 10 ng mL-1. The minimal detection limit was 0.01 ng mL-1. Due to its high sensitivity, acceptable stability and good selectivity, the immunosensor realized reliable quantification of RAC in real foodstuff. The proposed project has the potential to become a successful on-site screening method in food safety.

scholarly journals Deployment and Comparison of a Low-Cost High-Sensitivity Concentration Meters Using Micro-Optical Resonators

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 53
Author(s):  
Amir R. Ali ◽  
Maram Wael ◽  
Reem Amr Assal
Keyword(s):  
Chemical Composition ◽  
Morphological Changes ◽  
Low Cost ◽  
High Sensitivity ◽  
Single Mode ◽  
Optical Resonators ◽  
Optical Resonator ◽  
Single Mode Laser ◽  
Varied Chemical ◽  
Very High

Micro-optical resonators have been introduced as sensors in many applications for a wide number of variable types of stimuli due to their very high resolution, high sensitivity, and high-quality factor. In this paper, a novel micro-optical sensor was designed and tested as a concentration meter for chemical composition of a solution. The micro-optical resonator used is based on whispering gallery mode (WGM). This phenomenon appears when a tapered, single-mode laser carrying micro-optical fiber is evanescently coupled with a polymeric or silica micro-optical resonator. The presented sensor shows the change in concentration by experiencing a change in its morphology due to the varied viscosity of its environment. The variation of concentrations or fluid contents results in a change between the radii of the micro-optical resonator. With varied chemical composition and concentration in the tested sample varied infinitesimally small morphological changes are detected. The change in the resonators shape is read as a WGM shift in the resonance transmission spectrum, which is interpreted using a technique called cross-correlation, which compares the output across time to display the shift, which is later translated into distinct concentration levels. The proposed, exceptionally low-cost sensors were able to detect change at very high resolutions allowing better sensitivity along with wider range of variation. Experimental work for detection of ranges of concentrations of variable type of contaminants is presented.

A Novel and Simple Electrochemical Glucose Biosensor Based on a Silicon Nanowire Array Electrode

2014 ◽  
Author(s):  
Che-Wei Hsu ◽  
Wen-Chao Feng ◽  
Kang J. Chang ◽  
Gou-Jen Wang
Keyword(s):  
Low Cost ◽  
Silicon Nanowire ◽  
Nanowire Array ◽  
High Sensitivity ◽  
Glucose Biosensor ◽  
Glucose Detection ◽  
Redox Peak ◽  
Array Electrode ◽  
Silicon Nanowire Array ◽  
Very High

In this study, a novel and simple electrochemical glucose biosensor based on a silicon nanowire array (SNA) electrode was proposed. Metal-assisted etching (MAE) method using an AgNO3 and HF mixing solution as the etchant was employed to grow the silicon nanowire array (SNA) electrode. A thin gold shell is then sputtered over each silicon nanowire. Potassium ferricyanide, glucose oxidase (GOx), and a Nafion thin film were then sequentially coated onto the fabricated SNA for glucose detection. The processing time of the MAE and sputtering as well as the GOx concentration were optimized in terms of the redox peak currents of the SNA electrode. Compared with the corresponding plane gold electrode, the effective sensing area of the synthesized SNA electrode was measured to be 6.12 folds. Actual glucose detections demonstrated that the proposed SNA array electrode could operate in a linear range of 0.55 mM-11.02 mM and a very high sensitivity of 346 μA mM−1 cm−2. The proposed SNA electrode based glucose biosensor possesses advantages of simple fabrication process, low cost, and high sensitivity. It is feasible for future clinical applications.

Low-cost and high sensitivity glucose sandwich detection using a plasmonic nanodisk metasurface

Nanoscale ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 10809-10815 ◽  
Author(s):  
Zhongwen Long ◽  
Yuzhang Liang ◽  
Lei Feng ◽  
Hui Zhang ◽  
Mingze Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
High Sensitivity ◽  
Glucose Detection ◽  
Sensing Platform ◽  
Highly Sensitive

A low-cost, large scale plasmonic metasurface sensing platform shows enormous potential for highly sensitive and selective SERS-based glucose detection.

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