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Search results for: Amplite™ Fluorimetric Myelopeoxidase Assay Kit *Red Fluorescence*

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#38158478   2023/12/30 To Up

A Chromo-fluorogenic Probe for Selective Detection of Picric Acid Alongside Its Recovery by Aliphatic Amines and Construction of Molecular Logic Gates.

Nitroaromatic compounds are illicit explosive chemicals. For environmental security and homeland safety, selective and sensitive identification of these secondary-class explosives has been a reason for the exhaustive research arena of chemists for about a decade. We introduced a sensitive optical sensor with desalted neutral red (NR) dye. After ingressing picric acid (PA) in acetonitrile, the probe becomes non-fluorescent, displaying a colorimetric change from yellow to pink. The quenched phenomena and the changed color were re-established with aliphatic amine, trimethylamine (TEA). The reversibility is produced cyclically, both in fluorimetrically and spectrophotometrically. The detection limit for PA with our probe comes out as 0.639 µM; this value is significantly lower than many chemosensors available in the literature. Also, NR-stained filter paper strips-based test kit analysis has been deployed as a displayable photonic device for in-situ detection of PA. Furthermore, the whole system was conceptualized to produce single input, single output, and double input single output logic gates, which can be applied to digital devices. The chronological input manner as NTP (NR- TEA-PA) pushed us to configure a molecular keypad lock system, the basis of digital locking devices. The repeatable & reversible detection system exhibits "Write read- Erase-read Write-read' type memory devices.
Pallobi Sarkar, Najmin Tohora, Manas Mahato, Sabbir Ahamed, Tuhina Sultana, Sudhir Kumar Das

2516 related Products with: A Chromo-fluorogenic Probe for Selective Detection of Picric Acid Alongside Its Recovery by Aliphatic Amines and Construction of Molecular Logic Gates.

500 ml 10 mg 100 G20 ug 500 G 125 ml 10 mg 1 G 1 G

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#33855748   2021/05/05 To Up

Selective, pH-Dependent Colorimetric and Fluorimetric Detection of Quadruplex DNA with 4-Dimethylamino(phenyl)-Substituted Berberine Derivatives.

The 9- and 12-dimethylaminophenyl-substituted berberine derivatives 3 a and 3 b were readily synthesized by Suzuki-Miyaura reactions and shown to be useful fluorescent probes for the optical detection of quadruplex DNA (G4-DNA). Their association with the nucleic acids was investigated by spectrometric titrations, CD and LD spectroscopy, and with DNA-melting analysis. Both ligands bind to duplex DNA by intercalation and to G4-DNA by terminal π stacking. At neutral conditions, they bind with higher affinity (K =10 -10  M ) to representative quadruplex forming oligonucleotides 22AG, c-myc, c-kit, and a2, than to duplex calf thymus (ct) DNA (K =5-7×10  M ). At pH 5, however, the affinity of 3 a towards G4-DNA 22AG is higher (K =1.2×10  M ), whereas the binding constant towards ct DNA is lower (K =3.9×10  M ) than under neutral conditions. Notably, the association of the ligand with DNA results in characteristic changes of the absorption and emission properties under specific conditions, which may be used for optical DNA detection. Other than the parent berberine, the ligands do not show a noticeable increase of their very low intrinsic emission intensity upon association with DNA at neutral conditions. In contrast, a fluorescence light-up effect was observed upon association to duplex (Φ =0.01) and quadruplex DNA (Φ =0.04) at pH 5. This fluorimetric response to G4-DNA association in combination with the distinct, red-shifted absorption under these conditions provides a simple and conclusive optical detection of G4-DNA at lower pH.
Peter Jonas Wickhorst, Heiko Ihmels

2766 related Products with: Selective, pH-Dependent Colorimetric and Fluorimetric Detection of Quadruplex DNA with 4-Dimethylamino(phenyl)-Substituted Berberine Derivatives.

100tests100tests100tests100tests100tests100tests100tests100Tests2 x 96 well plate1 g100tests

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#26547433   2015/08/09 To Up

Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.

A quantitative immunoassay for the determination of immunoglobulin E (IgE) in human serum using gold nanoclusters (AuNCs) as fluorescent label was developed. Water soluble AuNCs were synthesized using lipoic acid and then thoroughly characterized. The obtained AuNCs have a particle size of 2.7 ± 0.1 nm and maximum fluorescence emission at 710 nm. The synthesized AuNCs showed very good stability of the fluorescent signal with light exposure and at neutral and slightly basic media. A covalent bioconjugation of these AuNCs with the desired antibody was carried out by the carbodiimide reaction. After due optimization of such bioconjugation reaction, a molar ratio 1:3 (antibody:AuNCs) was selected. The bioconjugate maintained an intense luminescence emission, slightly red-shifted as compared to the free AuNCs. Two typical immunoassay configurations, competitive and sandwich, were assayed and their performance for IgE determination critically compared. After the different immunoassay steps were accomplished, the fluorescence emission of the bioconjugate was measured. While the sandwich format provided a detection limit (DL) of 10 ng/mL and a linear range between 25 and 565 ng/mL of IgE, the competitive format revealed a DL of 0.2 ng/mL with a linear range between 0.3 and 7.1 ng/mL The applicability of the more sensitive competitive fluorescent immunoassay was assessed by successful analysis of the IgE in human serum and comparison of results with those from a commercial kit. The main advantages of the proposed AuNCs-based fluorimetric method include a low DL and a simple immunoassay protocol involving few reagents.
María Cruz Alonso, Laura Trapiella-Alfonso, José M Costa Fernández, Rosario Pereiro, Alfredo Sanz-Medel

2927 related Products with: Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.

1 kit100ug Lyophilized1 kit(96 Wells) 100ul430 tests100tests100ug Lyophilized96T1 kit(96 Wells)1 kit(96 Wells)100ug Lyophilized

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#22123491   2011/11/23 To Up

A protocol for in situ enzyme assays to assess the differentiation of human intestinal Caco-2 cells.

The Caco-2 cell line spontaneously differentiates into polarised enterocytes expressing high levels of brush border enzymes typical of small intestinal epithelial cells (peptidases, alkaline phosphatase, disaccharidases). The activities of these enzymes gradually increase after cell confluence reaching a plateau after 2-3 weeks of culture and can be used as reliable markers to evaluate differentiation of Caco-2 cells. We have developed a rapid in situ method on live cells to measure activities of alkaline phosphatase, alanyl amino peptidase and sucrase. The substrates were added to the apical compartment of confluent cells maintained for 8, 15 and 21 days on polycarbonate filter inserts and sampling was performed at time intervals. Alkaline phosphatase and alanyl aminopeptidase were assayed using as substrates p-Nitrophenyl phosphate and alanine-p-nitroanilide, respectively, and the yellow product detected spectrophotometrically at 405 nm. Sucrase activity was measured as the release of glucose from sucrose using a fluorimetric assay (Amplex® Red Glucose Assay Kit) in which H(2)O(2), produced by the coupled glucose oxidase/horseradish peroxidase reactions, oxidises the colourless reagent to red-fluorescent resorufin. All these assays are rapid and reproducible and can easily be adapted to robotised high throughput platforms.
Simonetta Ferruzza, Carlotta Rossi, Maria Laura Scarino, Yula Sambuy

2903 related Products with: A protocol for in situ enzyme assays to assess the differentiation of human intestinal Caco-2 cells.

96 assays100ug Lyophilized200 200ug5 x 50 ug100 20 ug100ug Lyophilized 100ul

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