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Search results for: Phosphate Colorimetric Assay Kit500 assays

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#33092495   2020/10/22 To Up

Cellular and biochemical antileukemic mechanisms of the meroterpenoid Oncocalyxone A.

Oncocalyxone A, a 1,4-benzoquinone derived from , exhibits anti-inflammatory, antimicrobial and antidiabetic properties. The aim of this study was to (1) examine the cytotoxic actions of oncocalyxone A on human normal and tumor cell lines and (2) determine mechanistic actions underlying effects upon leukemia cells using cellular and molecular techniques. Antiproliferative studies on cancer cell lines, peripheral blood mononuclear cells, and human erythrocytes were performed using colorimetric assays. To understand cytotoxicity, assessments were performed with HL-60 leukemia cells (8, 16.5, or 33 µM) after 24 hr incubation using light and fluorescence microscopy, trypan blue, flow cytometry, Comet assay, western blot of caspases and poly-ADP-ribose polymerase (PARP), and effects on topoisomerase I and II. Oncocalyxone A exhibited cytotoxic action upon HL-60 cells and dividing leukocytes, but minimal hemolytic action on erythrocytes. Mechanistic investigations demonstrated reduction of cell viability, loss of membrane integrity, cell shrinking, chromatin condensation, blebbings, externalization of phosphatidylserine, caspase activation, PARP cleavage, mitochondrial depolarization, and DNA damage. Pre-treatment with N-acetylcysteine 4 mM significantly reduced DNA damage and prevented membrane integrity loss. Oncocalyxone A displayed free radical dependent antileukemic activity via apoptotic pathways and induced DNA damage in HL-60 cells. Oncocalyxone A possesses structural chemical simplicity enabling it to be a cost-effective alternative. These properties justify further improvements to enhance activity and selectivity and the development of pharmaceutical formulations. Abbreviations Acridine orange, AO; ANOVA, analysis of variance; BSA, bovine serum albumin; DI, Damage Index; DMSO, dimethylsulfoxide; EC, effective concentration 50%; EDTA, ethylenediamine tetraacetic acid; EB, ethidium bromide; HCT-116, colon carcinoma line; HL-60, promyelocytic leukemia line; IC, inhibitory concentration 50%; MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; OVCAR-8, ovarian carcinoma line; NAC, N-acetylcysteine, PBMC, peripheral blood mononuclear cells; PBS, phosphate-buffered saline; PI, propidium iodide; PARP, poly-ADP-ribose polymerase; RPMI-1640, Roswell Park Memorial Institute medium; SF-295, glioblastoma line; ROS, reactive oxygen species; 7-AAD, 7-amino-actinomycin D; H-DCF-DA, 7'-dichlorodihydrofluorescein diacetate.
Aline Borba Sbardelotto, Francisco Washington Araújo Barros-Nepomuceno, Bruno Marques Soares, Bruno Coêlho Cavalcanti, Rayran Walter Ramos de Sousa, Marcília Pinheiro da Costa, Otília Deusdênia Loiola Pessoa, Cláudia Pessoa, Paulo Michel Pinheiro Ferreira

1574 related Products with: Cellular and biochemical antileukemic mechanisms of the meroterpenoid Oncocalyxone A.

5mg5mg100 mg3x 500 ml25mg 25 MG10mg100ul5mg

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#32796526   2020/08/11 To Up

Electrochemical Detection and Capillary Electrophoresis: Comparative Studies for Alkaline Phosphatase (ALP) Release from Living Cells.

Alkaline phosphatase (ALP) is one of the main biomarkers that is clinically detected in bone and liver disorders using optical assays. The electrochemical principle is important because point-of-care testing is increasing dramatically and absorbance techniques hardly compete with the medical revolution that is occurring. The detection of ALP using electrochemical detection is contributing to the integration systems field, and hence enhancing the detection of biological targets for pharmaceutical research and design systems. Moreover, in vitro electrochemical measurements use cost effective materials and simple techniques. Graphite screen-printed electrodes and linear sweep voltammetry were used to optimize the electrochemistry of the enzymatic product p-aminophenol using the enzyme kinetic assay. ALP release from embryonic and cancer cells was determined from adhesion cell culture. Additionally, capillary electrophoresis and colorimetric methods were applied for comparison assays. The resulting assays showed a dynamic range of ALP ranging from 1.5 to 1500 U/L, and limit of detection of 0.043 U/L. This was achieved by using 70 μL of the sample and an incubation time of 10 min at an optimal substrate concentration of 9.6 mM of p-aminophenol phosphate. A significant difference ( < 0.05) was measured between the absorbance assays. This paper demonstrates the advantages of the electrochemical assay for ALP release from cells, which is in line with recent trends in gene expression systems using microelectrode array technologies and devices for monitoring electrophysiological activity.
Thanih Balbaied, Anna Hogan, Eric Moore

2554 related Products with: Electrochemical Detection and Capillary Electrophoresis: Comparative Studies for Alkaline Phosphatase (ALP) Release from Living Cells.

100ug250ug1 ml100ul400/kit100ul1 mg2x96 well plate100ug1 ml1 kit100ul

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#32091879   2020/03/05 To Up

Alkaline Phosphatase-Triggered in Situ Formation of Silicon-Containing Nanoparticles for a Fluorometric and Colorimetric Dual-Channel Immunoassay.

Enzyme-triggered in situ chromogenic and/or fluorogenic reactions under accessible conditions are significant for developing enzyme activity and related spectroscopic assays. Here, we describe a facile one-pot synthetic strategy to prepare silicon-containing nanoparticles with yellow-green fluorescence and orange-red color by mixing -[3-(trimethoxysilyl)propyl]ethylenediamine and -aminophenol (AP) in aqueous solution at a mild temperature. Encouraged by the AP-regulated simple synthetic procedure and the generation of AP from alkaline phosphatase (ALP)-catalyzed hydrolysis of 4-aminophenol phosphate (APP), a fluorometric and colorimetric dual-readout ALP activity assay can be rationally envisioned and developed by employing APP as the substrate. In the wake of the good analytical performance of such ALP activity assay and its successful combination with enzyme-linked immunosorbent assay (ELISA), corresponding fluorometric and colorimetric dual-readout ALP-based ELISA has been constructed for highly sensitive and quantitative determination of human prostate-specific antigen (PSA), the key biomarker of prostate cancer in human serum. The convincing performance in evaluating the PSA level in serologic tests unambiguously reveals the great potential of our proposed fluorometric and colorimetric dual-channel immunoassay in early clinical diagnosis by monitoring disease biomarkers.
Chuanxia Chen, Dan Zhao, Bo Wang, Pengjuan Ni, Yuanyuan Jiang, Chenghui Zhang, Fan Yang, Yizhong Lu, Jian Sun

2703 related Products with: Alkaline Phosphatase-Triggered in Situ Formation of Silicon-Containing Nanoparticles for a Fluorometric and Colorimetric Dual-Channel Immunoassay.

100ul900 tests500 assays1 kit100ul100ul500 assays1 kit1 ml100ug150/kit 15 ml

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#32032848   2020/01/30 To Up

Tacrine-xanomeline and tacrine-iperoxo hybrid ligands: Synthesis and biological evaluation at acetylcholinesterase and M muscarinic acetylcholine receptors.

We synthesized a set of new hybrid derivatives (7-C8, 7-C10, 7-C12 and 8-C8, 8-C10, 8-C12), in which a polymethylene spacer chain of variable length connected the pharmacophoric moiety of xanomeline, an M/M-preferring orthosteric muscarinic agonist, with that of tacrine, a well-known acetylcholinesterase (AChE) inhibitor able to allosterically modulate muscarinic acetylcholine receptors (mAChRs). When tested in vitro in a colorimetric assay for their ability to inhibit AChE, the new compounds showed higher or similar potency compared to that of tacrine. Docking analyses were performed on the most potent inhibitors in the series (8-C8, 8-C10, 8-C12) to rationalize their experimental inhibitory power against AChE. Next, we evaluated the signaling cascade at M mAChRs by exploring the interaction of Gα-PLC-β3 proteins through split luciferase assays and the myo-Inositol 1 phosphate (IP1) accumulation in cells. The results were compared with those obtained on the known derivatives 6-C7 and 6-C10, two quite potent AChE inhibitors in which tacrine is linked to iperoxo, an exceptionally potent muscarinic orthosteric activator. Interestingly, we found that 6-C7 and 6-C10 behaved as partial agonists of the M mAChR, at variance with hybrids 7-Cn and 8-Cn containing xanomeline as the orthosteric molecular fragment, which were all unable to activate the receptor subtype response.
Marco Maspero, Daniela Volpato, Davide Cirillo, Natalia Yuan Chen, Regina Messerer, Christoph Sotriffer, Marco De Amici, Ulrike Holzgrabe, Clelia Dallanoce

2516 related Products with: Tacrine-xanomeline and tacrine-iperoxo hybrid ligands: Synthesis and biological evaluation at acetylcholinesterase and M muscarinic acetylcholine receptors.

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#31919598   2020/01/09 To Up

Colorimetric determination of the activity of alkaline phosphatase by exploiting the oxidase-like activity of palladium [email protected] core-shell nanoparticles.

Core-shell palladium [email protected] (Pd [email protected]) nanoparticles are shown to display oxidase-like activity. This is exploited in a method for determination of the activity of alkaline phosphatase (ALP). The Pd [email protected] nanoparticles were thermally synthesized from Ce(NO), L-arginine and preformed Pd cube seeds in water. The Pd [email protected] nanoparticles catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by oxygen. This results in the formation of oxidized TMB (oxTMB) with an absorption peak at 652 nm. Ascorbic acid (AA) is generated from the hydrolysis of L-ascorbic acid 2-phosphate (AAP) catalyzed by ALP. It can reduce oxTMB to TMB, and this results in a decrease of the absorbance. The method allows for quantitative determination of the activity of ALP in the range from 0.1 to 4.0 U·L and with a detection limit down to 0.07 U·L. Endowed with high sensitivity and selectivity, the assay can quantify ALP activity in biological system with satisfactory results. Graphical abstractSchematic illustration of Pd [email protected] core-shell nanoparticles for colorimetric determination of alkaline phosphatase.
Jiawei Wang, Pengjuan Ni, Chuanxia Chen, Yuanyuan Jiang, Chenghui Zhang, Bo Wang, Bingqiang Cao, Yizhong Lu

1167 related Products with: Colorimetric determination of the activity of alkaline phosphatase by exploiting the oxidase-like activity of palladium [email protected] core-shell nanoparticles.

100tests900 tests100Tests500 assays100tests100tests500 assays100 assays96 samples2 x 96 well plate2 x 96 well plate

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#31762263   2019/12/09 To Up

Engineering Two-Dimensional Pd Nanoplates with Exposed Highly Active {100} Facets Toward Colorimetric Acid Phosphatase Detection.

Enzyme-like activity and efficiency of nanomaterials are strongly controlled by their size, composition, and structure, and hence the structural parameters need to be optimized. Here, we report that two-dimensional Pd nanoplates enclosed by {100}-facets [{100}[email protected]] exhibit substantially enhanced intrinsic oxidase-like activities relative to the {111}-facets ones and Pd nanocubes in catalyzing the chromogenic reaction of 3,3',5,5'-tetramethylbenzidine. By taking ascorbic acid 2-phosphate as the substrate, which transforms to ascorbic acid in the presence of acid phosphatase (ACP), the {100}[email protected] could be used as an efficient nanozyme for colorimetric ACP detection without resorting to destructive HO. A good linear relationship from 0.01 to 6.0 mU/mL with a detection limit of 8.3 μU/mL is obtained, which is better than most previously reported ACP assays. Importantly, the excellent assay performance could be successfully applied to ACP determination in serum samples with high accuracy. This study demonstrates that the enzyme-like activity of nanomaterials could be finely tuned simultaneously by controlling their exposed crystal facets and high specific surface area.
Chuanxia Chen, Wendong Liu, Pengjuan Ni, Yuanyuan Jiang, Chenghui Zhang, Bo Wang, Jinkai Li, Bingqiang Cao, Yizhong Lu, Wei Chen

1228 related Products with: Engineering Two-Dimensional Pd Nanoplates with Exposed Highly Active {100} Facets Toward Colorimetric Acid Phosphatase Detection.

100tests500 assays100tests100tests 6 ml Ready-to-use 500 assays20 mg100tests100tests

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#31636936   2019/09/23 To Up

A paper-based microfluidic platform with shape-memory-polymer-actuated fluid valves for automated multi-step immunoassays.

Smart fluid manipulation with automatically controlled paper valves will enable automated and multi-step immunoassays on paper-based microfluidic devices. In this work, we present an integrated paper-based microfluidic platform with shape-memory polymer (SMP)-actuated fluid valves capable of automated colorimetric enzyme-linked immunosorbent assays (ELISAs). A single-layer microfluidic paper-based analytical device (μPAD) was designed to store all the reagents on the chip, and sequentially transfer reagents to a paper test zone following a specific ELISA protocol through automatic fluidic flow control by the multiple SMP-actuated valves. The actuation of a paper valve was based on the thermally responsive, duel-state shape transformation of a SMP sheet attached to the root of a paper cantilever beam for driving a hydrophilic paper bridge to connect and disconnect two paper channels. A portable colorimetric reader was developed to control the on-chip valve operations, quantify the colorimetric signal output, display the assay result, and wirelessly transmit the data to a smart phone for the application of telemedicine. Reliable operations of the paper valve and the entire μPAD were demonstrated with success rates of 97% and 93%, respectively. A detection mechanism for valve malfunction was designed and confirmed effective to identify any mal-operation of individual valves, thus rendering our platform reliable in real assays. For device calibration, we conducted direct ELISAs of rabbit IgG in phosphate-buffered saline (PBS), and achieved a low limit of detection (LOD) of 27 pM (comparable to that of standard and paper-based ELISAs). In order to demonstrate the clinical application of our multi-step immunoassay platform, we also conducted sandwich ELISAs to quantify the protein level of an inflammatory cytokine, namely tumor necrosis factor (TNF)-α, in surgically injured laryngeal tissues of rats. The protein levels of TNF-α were shown similar between the conventional and μPAD ELISAs.
Hao Fu, Pengfei Song, Qiyang Wu, Chen Zhao, Peng Pan, Xiao Li, Nicole Y K Li-Jessen, Xinyu Liu

1778 related Products with: A paper-based microfluidic platform with shape-memory-polymer-actuated fluid valves for automated multi-step immunoassays.

0.1 mg 8 ml 1 g0.1ml (1mg/ml)125 µg1 LITRE

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