Aptamer selection for the detection ofEscherichia coliK88

2011 ◽  
Vol 57 (6) ◽  
pp. 453-459 ◽  
Author(s):  
Hua Li ◽  
Xinghua Ding ◽  
Zhihui Peng ◽  
Le Deng ◽  
Dan Wang ◽  
...  
Keyword(s):  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Enterotoxigenic Escherichia Coli ◽  
Binding Ability ◽  
Single Stranded Dna ◽  
E Coli ◽  
Systematic Evolution ◽  
Selection For ◽  
K88 Fimbriae ◽  
Exponential Enrichment

In this study, the first group of single-stranded DNA aptamers that are highly specific to enterotoxigenic Escherichia coli (ETEC) K88 was obtained from an enriched oligonucleotide pool by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure, during which the K88 fimbriae protein was used as the target and bovine serum albumin as counter targets. These aptamers were applied successfully in the detection of ETEC K88. They were then grouped under different families based on the similarity of their secondary structure and the homology of their primary sequence. Four sequences from different families were deliberately chosen for further characterization by fluorescence analysis. Having the advantage of high sensitivity, fluorescence photometry was selected as single-stranded DNA quantification method during the SELEX process. Aptamers with the highest specificity and affinity were analyzed to evaluate binding ability with E. coli. Since ETEC K88 is the only type of bacterium that expressed abundant K88 fimbriae, the selected aptamers against the K88 fimbriae protein were able to specifically identify ETEC K88 among other bacteria. This method of detecting ETEC K88 by aptamers can also be applied to bacteria other than ETEC K88.

Differentiating breast cancer molecular subtypes using a DNA aptamer selected against MCF-7 cells

2018 ◽  
Vol 6 (12) ◽  
pp. 3152-3159 ◽  
Author(s):  
Mei Liu ◽  
Tong Yang ◽  
Zhongsi Chen ◽  
Zhifei Wang ◽  
Nongyue He
Keyword(s):  
Breast Cancer ◽  
Molecular Subtypes ◽  
Personalized Therapy ◽  
Dna Aptamer ◽  
Single Stranded Dna ◽  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Mcf 7

Aptamers are single-stranded DNA or RNA oligonucleotides selected by systematic evolution of ligands by exponential enrichment (SELEX), which show great potential in the diagnosis and personalized therapy of cancers, due to their specific advantages over antibodies.

Selection of aptamers specific for glycated hemoglobin and total hemoglobin using on-chip SELEX

Lab on a Chip ◽  
2015 ◽  
Vol 15 (2) ◽  
pp. 486-494 ◽  
Author(s):  
Hsin-I Lin ◽  
Ching-Chu Wu ◽  
Ching-Hsuan Yang ◽  
Ko-Wei Chang ◽  
Gwo-Bin Lee ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Glycated Hemoglobin ◽  
Dna Aptamers ◽  
Single Stranded Dna ◽  
Total Hemoglobin ◽  
Systematic Evolution ◽  
On Chip ◽  
Exponential Enrichment ◽  
Selection Of

Selection of blood glycated hemoglobin (HbA1c)- and total hemoglobin (Hb)-specific single-stranded DNA aptamers was performed on a microfluidic chip to continuously and automatically carry out multiple rounds of systematic evolution of ligands by exponential enrichment (SELEX) processes.

scholarly journals Aptamers selection for platelets using droplet digital PCR

2021 ◽  
pp. 100-103
Author(s):  
A.V. Blagodatova ◽  
◽  
K.V. Kochkina ◽  
M.A. Komarova ◽  
N.Y. Trofina ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Anticoagulant Activity ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Platelet Glycoprotein ◽  
Systematic Evolution ◽  
Selection For ◽  
Exponential Enrichment ◽  
Selection Of

The aim of the research. To obtain aptamers-inhibitors of platelet glycoprotein IIb / IIIa receptors, blocking platelet aggregation. Material and methods. Th e selection of aptamers for IIb / IIIa receptors of platelets was carried out according to the SELEX method (Systematic Evolution of Ligands by Exponential Enrichment), modifi ed to select aptamers for a specifi c epitope. Th e method allows selection and in vitro evolution of aptamers with selectivity to a specifi c target from a large library of oligonucleotides. Th e affi nity of aptamers for platelet IIb / IIIa receptors was determined using fl ow cytometry. Results. Pools of aptamers of aptamers with high affi nity for IIb / IIIa platelet receptors were obtained. Th e study of the antiaggregation properties of the pools with the best binding showed that platelet aggregation was minimal when using the aptamers from the pool of the 5th round of selection. Th us, the aptamers of this pool have the greatest potential to be used as an analogue of a synthetic peptide that blocks thromboaggregation. Aptamers from this pool were taken for sequencing in order to obtain sequences of aptamers with the best antiaggregatory properties. Conclusion. Pools of aptamers with high affi nity for IIb / IIIa receptors of platelets and anticoagulant activity were obtained.

scholarly journals Selection, Identification, and Application of Aptamers against Agaricus bisporus Lectin to Establish an Aptamer-AuNPs Colorimetric Method for Detection of ABL

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hao Gao ◽  
Yiling Tian ◽  
Min Zhang ◽  
Jianhui Liu ◽  
Yaowu Yuan ◽  
...  
Keyword(s):  
Agaricus Bisporus ◽  
Detection Method ◽  
Colorimetric Method ◽  
High Sensitivity ◽  
Antinutritional Factors ◽  
Detection Methods ◽  
Systematic Evolution ◽  
Novel Strategy ◽  
Exponential Enrichment ◽  
Current Detection

Agaricus bisporus lectin (ABL), which is one of the antinutritional factors in A. bisporus, is an important allergen and harmful to human health. Due to the shortcomings of the current detection methods, it is extremely urgent to establish a rapid and sensitive detection method for ABL in foods. To isolate the ssDNA aptamer of ABL, 13 rounds of subtractive systematic evolution of ligands by exponential enrichment (SELEX) selection were carried out. As a result, six candidate aptamers were selected and further examined for their binding affinity and specificity by enzyme-linked aptamer method. One aptamer (seq-41) against ABL with a high affinity and specificity was isolated and demonstrated to be the optimal aptamer whose dissociation constant reaches the nanomolar level, Kd = 31.17 ± 0.1070 nM. Based on seq-41, an aptamer-AuNPs colorimetric method was established to detect ABL with a linear range of 0.08∼1.70 μg/mL and the detection limit is 0.062 μg/mL. This study provides a novel aptamer-AuNPs colorimetric method with high sensitivity and specificity for detection of ABL and a novel strategy for development of detection method of fungal or plant allergens.

Single-stranded DNA aptamers that bind differentiated but not parental cells: subtractive systematic evolution of ligands by exponential enrichment

2003 ◽  
Vol 102 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Chenglong Wang ◽  
Ming Zhang ◽  
Guang Yang ◽  
Dajing Zhang ◽  
Hongmei Ding ◽  
...  
Keyword(s):  
Dna Aptamers ◽  
Single Stranded Dna ◽  
Systematic Evolution ◽  
Exponential Enrichment

scholarly journals High Specific DNAzyme-Aptamer Sensor for Salmonella paratyphi A Using Single-Walled Nanotubes–Based Dual Fluorescence-Spectrophotometric Methods

2014 ◽  
Vol 19 (7) ◽  
pp. 1099-1106 ◽  
Author(s):  
Yi Ning ◽  
WenKai Li ◽  
YingFen Duan ◽  
Ming Yang ◽  
Le Deng
Keyword(s):  
Detection Limits ◽  
Fluorescein Isothiocyanate ◽  
High Sensitivity ◽  
Dual Fluorescence ◽  
Spectrophotometric Methods ◽  
Absorbance Changes ◽  
Systematic Evolution ◽  
Aptamer Sensor ◽  
Exponential Enrichment ◽  
Dual Probe

In this work, single-stranded DNA aptamers that are highly specific to enterotoxigenic Salmonella paratyphi A were obtained from an enriched oligonucleotide pool using Systematic Evolution of Ligands by Exponential Enrichment (SELEX) to target the flagellin protein. The selected aptamers were confirmed to have high sensitivity and specificity to the flagellin. In addition, a probe (P0) containing the DNAzyme and fluorescein isothiocyanate–labeled aptamer3 sequences was employed as a dual probe for observing fluorescence and absorbance changes. The flagellin demonstrated low detection limits of 5 ng/mL by fluorescence and 20 ng/mL by spectrophotometry. Moreover, milk samples spiked with Salmonella paratyphi A were also detected, with the low detection limits increasing to 105 CFU/mL by fluorescence and 106 CFU/mL by spectrophotometry. The combination of fluorescence and spectrophotometry offers a specific, rapid, and sensitive way for detecting Salmonella paratyphi A and has potential for detecting other pathogens in food.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

Analysis of the monitoring study of the antibiotic-resistance of the agents of purulent-inflammatory processes of soft tissue

2018 ◽  
Vol 22 (2) ◽  
pp. 285-288
Author(s):  
A.P. Prevar ◽  
A.V. Kryzshanovskaya ◽  
V.A. Radionov ◽  
V.M. Mrug
Keyword(s):  
Soft Tissues ◽  
High Sensitivity ◽  
Biochemical Properties ◽  
Antimicrobial Drugs ◽  
Strict Adherence ◽  
E Coli ◽  
Monitoring Study ◽  
Treatment Measures ◽  
Inflammatory Processes ◽  
Main Factor

The main factor in the treatment of suppurative and inflammatory processes is the timely optimization of treatment measures taking into account the nature of the microflora and its susceptibility to antimicrobial drugs. The purpose of the study is to monitor the spectrum of microorganisms – pathogens of purulent-inflammatory processes of soft tissues in surgical patients; study of the sensitivity of isolated strains to antibiotics. The material was collected in accordance with aseptic rules. The identification of a pure culture of bacteria was carried out according to morphological, culture, biochemical properties, and the presence of virulence enzymes. Sensitivity of bacteria to antibiotics was determined by the standard disks method (by Kirby-Bauer’s). 255 patients with purulent-inflammatory processes of soft tissues were examined for the period from 2014 to 2017. 229 strains of isolated bacteria were included to Escherichia coli, Citrobacer freundii, Enterobacter cloacae, E.aerogenes, Proteus vulgaris, Staphylococcus aureus, S.epidermidis, Streptococcus pyogenes, S.viridians, S.agalactiae, Pseudomonas aeruginosa. The main cause of purulent-inflammatory processes of soft tissues is Staphylococci (67,2%). Compared to previous studies, the number of P.aeruginosa isolated cultures increased (7.9%). In monoculture and in association with other microorganisms, E. coli (9.6% of cases), E.cloacae et aerogenes (3.9% of cases), P.vulgaris (3.9% of cases), C.freundi (2.5% of cases), S.agalactiae, S.pyogenes, S.viridans (3.5%). The number of associated sows reaches 12%. Clinical strains of microorganisms remain most sensitive to fluoroquinolones, cephalosporins, and also retains high sensitivity to gentamicin, lincomycin, rifampicin, which is important for empirical antibiotic therapy. To increase the effectiveness of antibacterial therapy, strict adherence to the mode of appointment of antibiotics, justification of indications, a combination of antibiotics of different spectrum of action, mandatory correction after determining the sensitivity of the pathogen.

Sign in / Sign up

Export Citation Format

Share Document