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New Zealand — Anion detection in capillary electrophoresis with ion-selective microelectrodes
Biosensors & Bioelectronics VoL 10 No. 1/2 (1995)
USA - Cadmiun ion detection using fluorescence probe Indo-1
U S A - Microfabrication in silicon microphysiometry
In ANAL. CHIM. ACTA (295/1-2 (67-72) 1994) T. Vo-Dinh, P. Viallet, L. Ramirez, A. Pal, J. Vigo of Oak Ridge National Laboratory report on "Detection of cadmium ion using the fluorescence probe Indo- 1". Fluorescence probes for biosensors used for the determination ofintracellular concentration of metal ions have been synthesized in order to bind selectively with a specific cation. Since certain ions exhibit similar chemical properties, binding selectivity with the probes is difficult. For the first time the i n t e r a c t i o n b e t w e e n Indo-1, a fluorescence probe representative of a family of 'specific chelating compounds' (mainly used for calcium) with the cadmium ion is characterized. The fluorescence properties of the cadmium complex are described and a method is proposed to determine the concentrations of both calcium and cadmium ions in aqueous solutions.
In CLIN. CHEM. (40/9 (1800-1804) 1994) G.T. Baxter, L.J. Bousse, T.D. Dawes, J.M. Libby, D.N. Modlin, J.C. Owicki, J.W. Parce of M o l e c u l a r D e v i c e s Corp report on "Microfabrication in silicon microphysiometry". Over the past 5 years, microphysiometry has proved an effective means for detecting p h y s i o l o g i c a l changes in cultured cells, particularly as a functional assay for the activation of many cellular receptors. To demonstrate the clinical relevance of this method it was used to detect bacterial antibiotic sensitivity and to d i s c r i m i n a t e b e t w e e n bacteriostatic and bacteriocidal concentrations. The light-addressable potentiometric sensor, upon which microphysiometry is based, is well suited for structural m a n i p u l a t i o n s based on photolithography and micromachining, and we have begun to take advantage of this capability. Results are presented from a research instrument with eight separate assay channels on a 5-cm 2 chip. The planned evolution of the technology toward h i g h - t h r o u g h p u t instruments and instruments capable of performing single-cell measurements is discussed.
Contact: Advanced Monitoring Developm. Group, Health and Safety Research Dh4sion, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6101, USA New Zealand - Anion detection in capillary electrophoresis with ion-selective microelectrodes In ANAL. CHIM. ACTA (295/1-2 (181-186) 1994) P.C. Hauser, N.D. Renner, A.P.C. Hong of the University of Auckland report on "Anion detection in capillary electrophoresis with ion-selective microelectrodes". The use of potentiometric microelectrodes as detectors for anions in capillary electrophoresis is demonstrated. The detector electrode with a tip diameter of 3 t.tm is inserted into the end of a fused silica separation capillary with an internal diameter of 25 ~tm. The separation and detection of CI-, NO3, NO~, Br-, I- and ClOg down to concentrations of 10 l.tg kg -1 is reported.
Contact: Department of Chemistry, University of Auckland, Private Bag 92019, Auckland, New Zealand
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Contact: Molecular Devices Corp., 1311 Orleans Dr., Sunnyvale, CA 94089, USA Italy - Ion-selective electrode: Reliability and application In G. ITAL. NEFROL. (11/4 (253-264) 1994) L. Pedrini, S. Felini, G. Cozzi, P. Faranna, L. Spandrio of Servizio di Nefrologia i Dialisi, Sondrio report on "Ion-selective electrode measurements of sodium activity in dialysis: Reliability and application to sodium kinetic models". Factors affecting sodium determinations with direct potentiometry were assessed in 15 patients on dialysis to verify if the method allows measuring the effective gradient of ionic activity of Na between plasma water and dialysate, thus to calculate its transfer by diffusion and its net balance of the session. As expected, changes in
USA - Cadmiun ion detection using fluorescence probe Indo-1
U S A - Microfabrication in silicon microphysiometry
In ANAL. CHIM. ACTA (295/1-2 (67-72) 1994) T. Vo-Dinh, P. Viallet, L. Ramirez, A. Pal, J. Vigo of Oak Ridge National Laboratory report on "Detection of cadmium ion using the fluorescence probe Indo- 1". Fluorescence probes for biosensors used for the determination ofintracellular concentration of metal ions have been synthesized in order to bind selectively with a specific cation. Since certain ions exhibit similar chemical properties, binding selectivity with the probes is difficult. For the first time the i n t e r a c t i o n b e t w e e n Indo-1, a fluorescence probe representative of a family of 'specific chelating compounds' (mainly used for calcium) with the cadmium ion is characterized. The fluorescence properties of the cadmium complex are described and a method is proposed to determine the concentrations of both calcium and cadmium ions in aqueous solutions.
In CLIN. CHEM. (40/9 (1800-1804) 1994) G.T. Baxter, L.J. Bousse, T.D. Dawes, J.M. Libby, D.N. Modlin, J.C. Owicki, J.W. Parce of M o l e c u l a r D e v i c e s Corp report on "Microfabrication in silicon microphysiometry". Over the past 5 years, microphysiometry has proved an effective means for detecting p h y s i o l o g i c a l changes in cultured cells, particularly as a functional assay for the activation of many cellular receptors. To demonstrate the clinical relevance of this method it was used to detect bacterial antibiotic sensitivity and to d i s c r i m i n a t e b e t w e e n bacteriostatic and bacteriocidal concentrations. The light-addressable potentiometric sensor, upon which microphysiometry is based, is well suited for structural m a n i p u l a t i o n s based on photolithography and micromachining, and we have begun to take advantage of this capability. Results are presented from a research instrument with eight separate assay channels on a 5-cm 2 chip. The planned evolution of the technology toward h i g h - t h r o u g h p u t instruments and instruments capable of performing single-cell measurements is discussed.
Contact: Advanced Monitoring Developm. Group, Health and Safety Research Dh4sion, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6101, USA New Zealand - Anion detection in capillary electrophoresis with ion-selective microelectrodes In ANAL. CHIM. ACTA (295/1-2 (181-186) 1994) P.C. Hauser, N.D. Renner, A.P.C. Hong of the University of Auckland report on "Anion detection in capillary electrophoresis with ion-selective microelectrodes". The use of potentiometric microelectrodes as detectors for anions in capillary electrophoresis is demonstrated. The detector electrode with a tip diameter of 3 t.tm is inserted into the end of a fused silica separation capillary with an internal diameter of 25 ~tm. The separation and detection of CI-, NO3, NO~, Br-, I- and ClOg down to concentrations of 10 l.tg kg -1 is reported.
Contact: Department of Chemistry, University of Auckland, Private Bag 92019, Auckland, New Zealand
xii
Contact: Molecular Devices Corp., 1311 Orleans Dr., Sunnyvale, CA 94089, USA Italy - Ion-selective electrode: Reliability and application In G. ITAL. NEFROL. (11/4 (253-264) 1994) L. Pedrini, S. Felini, G. Cozzi, P. Faranna, L. Spandrio of Servizio di Nefrologia i Dialisi, Sondrio report on "Ion-selective electrode measurements of sodium activity in dialysis: Reliability and application to sodium kinetic models". Factors affecting sodium determinations with direct potentiometry were assessed in 15 patients on dialysis to verify if the method allows measuring the effective gradient of ionic activity of Na between plasma water and dialysate, thus to calculate its transfer by diffusion and its net balance of the session. As expected, changes in