National Repository of Grey Literature 24 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Epitachophoretic separation and concentration of large volume samples
Voráčová, Ivona ; Foret, František ; Datinská, Vladimíra ; Novotný, Jakub ; Gheibi, P. ; Berka, J. ; Astier, Y.
There has been a growing interest in developing isotachophoretic protocols for concentration and purification of DNA as an alternative to the solid phase extraction protocols of DNA preparation. Also concentration of DNA from large volume samples is required. We have developed a new device suitable for separation, concentration and collection of ions from several milliliter sample volumes into microliter fractions. We have used a discontinuous electrolyte system comprising of the leading and terminating electrolytes utilized for concentration of samples containing DNA fragments. The method is simple, fast with high concentration factor and without extensive surface interactions.
Surface enhanced raman spectroscopy: Detection platforms for sample analysis with and without electrophoretic separation
Týčová, Anna ; Přikryl, Jan ; Foret, František ; Belder, D.
In this work we present two platforms of relatively simple construction for user-friendly sample detection via surface enhanced Raman spectroscopy (SERS). The first platform is designed for direct sample analysis and deals with hydrophilic spots array within a hydrophobic surface. The second presented platform aims on analysis of samples of higher complexity requiring separation step prior the detection. This is achived via microfluidic electrophoretic device with online SERS detection.
A New evaluation of combined antitumor effects of natural and synthetic nuclear retinoid receptor ligands in human breast carcinoma cells
Strouhalová, Dana ; Laštovičková, Markéta ; Bobál, P. ; Macejová, D. ; Mosná, B. ; Brtko, J. ; Bobálová, Janette
This work represents the study of the effects of biologically active ligands of nuclear retinoid X receptors, triorganotin compounds, on proteomic profile of MDA-MB-231 cells. We focused primarily on tributyl/phenyltin derivatives that suggest the combined antitumor effect when they are used with natural nuclear retinoid receptor ligand all-trans retinoic acid (ATRA). Proteomic strategies connected to PDQuest evaluation were applied in this study. Some specific proteins with tumor process association were chosen for more detail study. Our findings indicate that selected triorganotins derivatives resulted to significantly reduced level of studied proteins belonging to metabolic pathway or to other cellular processes as apoptosis or epithelial–mesenchymal transition. In the case of vimentin, the key protein of EMT process, the silencing was set up by triorganotin compounds and significantly enhanced by combination with ATRA. This additive effect on downregulation can result from the potential engagement of RXR/RAR heterodimer, considering co-addition of both partner ligands of mentioned heterodimer to the treatment.
Maximizing efficiency of field-amplified electrokinetic injection of weak bases for enantioselective capillary electrophoresis with sulfated cyclodextins
Šesták, Jozef ; Thormann, W.
The optimal conditions for field-amplified electrokinetic injection of cations followed by their separation based on the stereoselective interaction with sulfated cyclodextrins are discussed. Results show that addition of a short water plug together with a short plug free of cyclodextrins and with a buffer concentration similar to the BGE greatly increase the injection efficiency.
Rapid fabrication of microextraction devices for direct determination of basic drugs in dried blood spots
Ryšavá, Lenka ; Přikryl, Jan ; Dvořák, Miloš ; Malá, Zdeňka ; Kubáň, Pavel
A 3D-printed cutter was designed for rapid fabrication of supported liquid membrane (SLM) extraction devices compatible with injection system of commercial capillary electrophoresis (CE) instrument. Low cost and single use microextraction devices were fabricated from polypropylene micropipette tips with high precision (dimension variances ≤ 3% RSD). Practical applicability of the microextraction devices was examined by in-line coupling of SLM extractions to CE for direct analysis of four model basic drugs in dried blood spot extracts. Excellent repeatability of the hyphenated technique was achieved (RSD ≤ 7.6%), transfer of analytes across the SLM ranged from 23 to 73% and limits of detection were as low as 0.07 μg/mL.
Arduino-based pressure-driven flow controller for droplet microfluidics
Přikryl, Jan ; Křivánková, Jana ; Hlaváček, Antonín
Droplet-based microfluidic systems bear significant value in an extremely wide range of applications due to its remarkable advantages, nevertheless, their technical demands on precise flow control are high. Here, we present lab-built Arduino-based flow controller fulfilling needs of droplet microfluidics to easily and effectively automate the system. As an additional required accessory, CNC-milled component for vials pressurizing was presented.
Hexahistidine-based tag for capillary electrophoresis-mass spektrometry analysis of oligosaccharides and N-linked glycans
Partyka, Jan ; Křenková, Jana ; Čmelík, Richard ; Foret, František
Various basic amino acids and peptides were studied as an alternative labels for capillary electrophoresis-mass spectrometry analysis of oligosaccharides. The hexahistidine-based label with big number of positive charges allowed to use effective and sensitive CE-MS analysis in positive ion mode both neutral and acidic glycans.
Affinity microfluidic chip based on packed microbeads
Novotný, Jakub ; Ostatná, Veronika ; Foret, František
In this project, a plastic device was fabricated using CNC milling in polycarbonate. Chip contains integrated pneumatic valves for flow control and allows for injection and stacking of beaded supports. Intended use of these supports is formation of packed affinity columns suitable for glycoprotein assays.
A Microfluidic devide for monitoring cell migration
Ledvina, Vojtěch ; Klepárník, Karel ; Legartová, Soňa ; Bártová, Eva
A polydimethylsiloxane microfluidic device for monitoring directed cell migration was developed. The device comprises a main channel barred by pillar arrays with decreasing spacing and utilizes chemotactic movement of cells in the direction of increasing gradient of fetal bovine serum. HeLa cell line transfected with Premo FUCCI Cell Cycle Sensor was used as a model organism. The cells were imaged for several days using a scanning confocal microscope and the rate of migration in different cell cycle phases was evaluated.
Acetonitrile-assisted enzymatic digestion used for analysis of proteins of cancer origin
Laštovičková, Markéta ; Bobál, P. ; Strouhalová, Dana ; Bobálová, Janette
In this study, in-gel trypsin digestion protocol using aqueous-acetonitrile solvent system was developed to facilitate bottom-up proteomic identification of proteins isolated from human breast cancer cells.

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