University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Microscopy

Classification: Microscopy

Citations 4

"Flow Injection Microscopy: A Novel Tool For The Study Of Cellular Response And Drug Discovery"
Analyst 1996 Volume 121, Issue 7 Pages 945-950

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Jaromir Ruzicka, Pamela J. Baxter, Ole Thastrup and Kurt Scudder

Abstract: Flow injection (FI) microscopy was used to study the responses of living cells in an inverted radial flow chamber to repeated stimulations of a biologically active ligand. Baby hamster kidney cells (BHK-570) transfected with muscarinic Ml receptor were used. Carbachol and acetylcholine were used as agonists and the cellular responses were monitored as the release of intracellular Ca using fura-2 acetoxymethyl ester was the molecular probe. The use of FI microscopy enabled the kinetics of receptor binding and cellular responses to be studied in a controlled and reproducible fashion. The potential of the technique for drug screening (efficacy) studies through monitoring of the initial kinetics of cellular responses was also demonstrated.

"Jet Ring Cell: A Tool For Flow Injection Spectroscopy And Microscopy On A Renewable Solid Support"
Anal. Chem. 1993 Volume 65, Issue 24 Pages 3566-3570

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Jaromir Ruzicka, Cy H. Pollema, and Kurt M. Scudder

Abstract: The cited flow-cell is described and illustrated. It exploits radial flow-through a narrow ring-shaped gap (20-50% of the particle diameter) to retain suspended particles within a well-defined detection region; trapped particles can be removed instantaneously by flow reversal. The cell was characterized by analysis of various beads (e.g., Polysorb MP1 and Sephadex) stained with dyes or fluorescent reagents and suspended in suitable buffers, using a sequential injection system with a flow-rate of 2.5 ml/min, a reverse flow-rate of 10 ml/min, a carrier solution of 0.01 M sodium borate buffer and a microscope system equipped with an epifluorescence attachment (details given). Cytodex 3 beads covered by adherent, stained BHK cells were also used with a carrier solution of HEPES buffer. The cell should prove useful for automated immunoassays and monitoring the pre-concentration of analytes on sorbents. A new flow cell design for spectroscopic measurements of suspensions, the jet ring cell, is introduced. This cell exploits radial flow-through a narrow ring-shaped gap to retain suspended particles within the detection region. This ring constitutes a detection volume of well- defined area from which the trapped particles can be instantaneously removed at will. The bed of particles thus forms a renewable surface, which can be probed by reflectance, fluorescence, or chemiluminescence using a microscope or optical fiber. This device should prove useful for microscopic study of cells, for automated immunoassays, and for pre-concentration of analytes on sorbents with in situ spectroscopic detection. In conjunction with a fiber optic detection system, the jet ring cell becomes a component of a renewable chemical sensor system.
Flowcell Preconcentration Immobilized reagent Jet ring cell Solid phase detection Optical fiber Renewable surface Sephadex

"Rapid, Reproducible Perfusion For Optical Microscopy Using Flow Injection Techniques"
Molecul. Biol. Cell 1992 Volume 3, Issue S Pages A91-A91

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Scudder, K.M.;Ruzicka, J.;Christian, G.D.;Pagliaro, L.

Abstract: Rapid exchange of the medium surrounding cells is an essential tool for many cell physiological experiments. Typical microscope perfusion chamber designs represent a compromise between optical considerations, flow requirements, and shear stress on the cells; optical constraints imposed by DIC microscopy are often favored at the expense of flow characteristics necessary for rapid exchange of media. We have developed a perfusion chamber which enables fast, reproducible medium exchange under controlled shear conditions. Our chamber is best suited for high numerical aperture epifluorescence microscopy and phase contrast microscopy with a long working distance condenser, but it cannot be used for DIC microscopy. Complete exchange of the medium over a 12 mm diameter area of the cover slip can be accomplished in several seconds, and the medium over a typical microscope field can be exchanged in about 1 second, with shear rates that will not damage adherent cells (0.1 - 3.0 dyn/cm2). The combination of this chamber with the Flow Injection technique, which is widely used in analytical chemistry, provides a highly versatile tool for microscopy. Experiments requiring complex perfusion profiles may be run under computer control with better than 1% reproducibility of the concentration profile from run to run. This technique is a significant improvement for cell physiological experiments requiring rapid, precise environmental control on the microscope stage. (Supported by N.I.H. grant SSS-3 (S) ROl GM 45260-2.)
Perfusion

"Integrated Multilayer Flow System On A Microchip"
Anal. Sci. 2001 Volume 17, Issue 1 Pages 89-93

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Akihide Hibara, Manabu Tokeshi, Kenji Uchiyama, Hideaki Hisamoto And Takehiko Kitamori

Abstract: We utilized microchip technology and found that the multilayer flow of liquids can be formed in microchannels. Liquid/liquid interfaces were formed parallel to the side wall of the microchannels, because the surface tension and friction force are stronger than the force of gravity. A water/ethylacetate/water interface was formed in a 70 µm-wide and 30 µm-deep channel. The interface was observed to be quite stable and to be maintained for a distance of more than 18 cm. As an example of a multilayer flow application, we demonstrated the liquid/liquid extraction of Co-dimethylaminophenol complex in a microchannel. The solvent-extraction process of the complex into m-xylene in the multilayer flow was found to reach equilibrium in 4 s, while it took 60 s in a simple two-phase extraction.
Cobalt Microfluidic Extraction