A highly efficient Baby Spinach-based minimal modified sensor (BSMS) for nucleic acid analysis

2019 ◽  
Vol 17 (30) ◽  
pp. 7222-7227 ◽  
Author(s):  
Rashi Soni ◽  
Deepti Sharma ◽  
A. Murali Krishna ◽  
Jagadeesh Sathiri ◽  
Ashwani Sharma
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
High Selectivity ◽  
Fluorescence Enhancement ◽  
Highly Efficient ◽  
Nucleic Acid Analysis ◽  
Modified Sensor

A Baby Spinach aptamer based minimal-modified sensor (BSMS) detects nucleic acids of potentially any length with high selectivity and specificity, and shows 2.5-fold more fluorescence enhancement compared to the parent aptamer.

Nucleic acids in prion preparations: unspecific background or essential component?

1994 ◽  
Vol 343 (1306) ◽  
pp. 425-430 ◽  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Large Scale ◽  
Size Range ◽  
Complete Recovery ◽  
Tissue Homogenate ◽  
Purification Step ◽  
Prolonged Incubation ◽  
Purification Scheme ◽  
Nucleic Acid Analysis

As recently published (Kellings et al. J. gen Vir. 73, 1025-1029 (1992)), the analysis of purified scrapie prions by return refocusing gel electrophoresis revealed remaining nucleic acids in the size range up to 1100 nucleotides. The results defined the possible characteristics of a hypothetical scrapie-specific nucleic acid. If homogeneous in size, such a molecule would be less than 80 nucleotides in length at a particle-toinfectivity ratio (p: i) near unity; if heterogeneous, scrapie-specific nucleic acids would have to include molecules smaller than 240 nucleotides. To decrease the amount of nucleic acids, several modifications of the PrP Sc purification scheme were introduced. Instead of sucrose gradient, ultrafiltration was applied as a purification step and nucleic acids were degraded by BenzonasetM after ultrafiltration, but significant reduction of the p: i ratio could not be achieved. To prevent trapping of nucleic acids in prion rods, nuclease (Benzonase™ ) was added into the tissue homogenate and incubated at 37°C, overnight. The Benzonase treatment revealed no loss of infectivity, but the whole procedure of nucleic acid analysis did not lead to a reduction of the p :i ratio. In another approach the number of nucleic acid degradations steps was reduced to essentially two steps: Zn 2+ hydrolysis and Benzonase digestion. Higher Zn 2+ concentrations and prolonged incubation times resulted in a more efficient nucleic acid degradation. The bioassays yielded complete recovery of infectivity. Large-scale preparations for determining the p: i ratio are still underway

scholarly journals Nucleic acid-based biosensors: analytical devices for prevention, diagnosis and treatment of diseases

Revista Vitae ◽  
2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Laura Carvajal Barbosa ◽  
Diego Insuasty Cepeda ◽  
Andrés Felipe León Torres ◽  
Maria Mercedes Arias Cortes ◽  
Zuly Jenny Rivera Monroy ◽  
...  
Keyword(s):  
Food Safety ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Pathogenic Bacteria ◽  
High Selectivity ◽  
Low Cost ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Disease Status ◽  
Public Health Issue

BACKGROUND : Biosensing techniques have been the subject of exponentially increasing interest due to their performance advantages such as high selectivity and sensitivity, easy operation, low cost, short analysis time, simple sample preparation, and real-time detection. Biosensors have been developed by integrating the unique specificity of biological reactions and the high sensitivity of physical sensors. Therefore, there has been a broad scope of applications for biosensing techniques, and nowadays, they are ubiquitous in different areas of environmental, healthcare, and food safety. Biosensors have been used for environmental studies, detecting and quantifying pollutants in water, air, and soil. Biosensors also showed great potential for developing analytical tools with countless applications in diagnosing, preventing, and treating diseases, mainly by detecting biomarkers. Biosensors as a medical device can identify nucleic acids, proteins, peptides, metabolites, etc.; these analytes may be biomarkers associated with the disease status. Bacterial food contamination is considered a worldwide public health issue; biosensor-based analytical techniques can identify the presence or absence of pathogenic agents in food. OBJECTIVES: The present review aims to establish state-of-the-art, comprising the recent advances in the use of nucleic acid-based biosensors and their novel application for the detection of nucleic acids. Emphasis will be given to the performance characteristics, advantages, and challenges. Additionally, food safety applications of nucleic acid-based biosensors will be discussed. METHODS: Recent research articles related to nucleic acid-based biosensors, biosensors for detecting nucleic acids, biosensors and food safety, and biosensors in environmental monitoring were reviewed. Also, biosensing platforms associated with the clinical diagnosis and food industry were included. RESULTS: It is possible to appreciate that multiple applications of nucleic acid-based biosensors have been reported in the diagnosis, prevention, and treatment of diseases, as well as to identify foodborne pathogenic bacteria. The use of PNA and aptamers opens the possibility of developing new biometric tools with better analytical properties. CONCLUSIONS: Biosensors could be considered the most important tool for preventing, treating, and monitoring diseases that significantly impact human health. The aptamers have advantages as biorecognition elements due to the structural conformation, hybridization capacity, robustness, stability, and lower costs. It is necessary to implement biosensors in situ to identify analytes with high selectivity and lower detection limits.

scholarly journals Noninvasive Prenatal Diagnosis of Fetal Chromosomal Aneuploidies by Maternal Plasma Nucleic Acid Analysis

2008 ◽  
Vol 54 (3) ◽  
pp. 461-466 ◽  
Author(s):  
Y M Dennis Lo ◽  
Rossa W K Chiu
Keyword(s):  
Prenatal Diagnosis ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Maternal Plasma ◽  
Small Sample ◽  
Routine Practice ◽  
Allelic Ratio ◽  
Noninvasive Prenatal Diagnosis ◽  
Nucleic Acid Analysis ◽  
Chromosomal Aneuploidies

Abstract Background: The discovery of circulating cell-free fetal nucleic acids in maternal plasma has opened up new possibilities for noninvasive prenatal diagnosis. The potential application of this technology for the noninvasive prenatal detection of fetal chromosomal aneuploidies is an aspect of this field that is being actively investigated. The main challenge of work in this area is the fact that cell-free fetal nucleic acids represent only a minor fraction of the total nucleic acids in maternal plasma. Methods and Results: We performed a review of the literature, which revealed that investigators have applied methods based on the physical and molecular enrichment of fetal nucleic acid targets from maternal plasma. The former includes the use of size fractionation of plasma DNA and the use of the controversial formaldehyde treatment method. The latter has been achieved through the development of fetal epigenetic and fetal RNA markers. The aneuploidy status of the fetus has been explored through the use of allelic ratio analysis of plasma fetal epigenetic and RNA markers. Digital PCR has been shown to offer high precision for allelic ratio and relative chromosome dosage analyses. Conclusions: After a decade of work, the theoretical and practical feasibility of prenatal fetal chromosomal aneuploidy detection by plasma nucleic acid analysis has been demonstrated in studies using small sample sets. Larger scale independent studies will be needed to validate these initial observations. If these larger scale studies prove successful, it is expected that with further development of new fetal DNA/RNA markers and new analytical methods, molecular noninvasive prenatal diagnosis of the major chromosomal aneuploidies could become a routine practice in the near future.

scholarly journals Design and enhanced gene silencing activity of spherical 2′-fluoroarabinose nucleic acids (FANA-SNAs)

2021 ◽  
Author(s):  
Hassan H. Fakih ◽  
Adam Katolik ◽  
Elise Malek-Adamian ◽  
Johans J. Fakhoury ◽  
Sepideh Kaviani ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Gene Silencing ◽  
Nucleic Acid Therapeutics ◽  
Highly Efficient ◽  
Efficient Delivery ◽  
Spherical Nucleic Acids

Optimizing FANA modified spherical nucleic acids (FANA-SNAs) for highly efficient delivery of nucleic acid therapeutics.

scholarly journals Three-Way Junction-Induced Isothermal Amplification with High Signal-to-Background Ratio for Detection of Pathogenic Bacteria

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4132
Author(s):  
Jung Ho Kim ◽  
Seokjoon Kim ◽  
Sung Hyun Hwang ◽  
Tae Hwi Yoon ◽  
Jung Soo Park ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Pathogenic Bacteria ◽  
High Selectivity ◽  
Isothermal Amplification ◽  
Rna Aptamers ◽  
High Signal ◽  
Fluorescence Signal ◽  
Enhanced Fluorescence ◽  
Target Nucleic Acid

The consumption of water and food contaminated by pathogens is a major cause of numerous diseases and deaths globally. To control pathogen contamination and reduce the risk of illness, a system is required that can quickly detect and monitor target pathogens. We developed a simple and reproducible strategy, termed three-way junction (3WJ)-induced transcription amplification, to detect target nucleic acids by rationally combining 3WJ-induced isothermal amplification with a light-up RNA aptamer. In principle, the presence of the target nucleic acid generates a large number of light-up RNA aptamers (Spinach aptamers) through strand displacement and transcription amplification for 2 h at 37 °C. The resulting Spinach RNA aptamers specifically bind to fluorogens such as 3,5-difluoro-4-hydroxybenzylidene imidazolinone and emit a highly enhanced fluorescence signal, which is clearly distinguished from the signal emitted in the absence of the target nucleic acid. With the proposed strategy, concentrations of target nucleic acids selected from the genome of Salmonellaenterica serovar Typhi (S. Typhi) were quantitatively determined with high selectivity. In addition, the practical applicability of the method was demonstrated by performing spike-and-recovery experiments with S. Typhi in human serum.

Slip Formation of a High-Density Droplet Array for Nucleic Acid Quantification by Digital LAMP with a Random Access System

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Weiyuan Lyu ◽  
Jiajie Zhang ◽  
Yan Yu ◽  
Lei Xu ◽  
Feng Shen
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Random Access ◽  
High Density ◽  
Access System ◽  
System P ◽  
Droplet Array ◽  
Precise Quantification ◽  
Nucleic Acid Analysis

Digital nucleic acid analysis (digital NAA) is an important tool for the precise quantification of nucleic acids. Various microfluidic-based approaches for digital NAA have been developed, but most methods either...

Nucleic Acid Molecules Prepared by Monolayer Techniques

1972 ◽  
Vol 30 ◽  
pp. 178-179
Author(s):  
Dimitrij Lang
Keyword(s):  
Electron Microscopy ◽  
Standard Deviation ◽  
Nucleic Acid ◽  
Cytochrome C ◽  
Nucleic Acids ◽  
Contour Length ◽  
Sample Standard Deviation ◽  
Molecular Weights ◽  
Length Measurements ◽  
Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

Sign in / Sign up

Export Citation Format

Share Document