In situ fiber-optical monitoring of cytosolic calcium in tissue explant cultures

• Published in: Journal of biophotonics Vol. 8; no. 3; pp. 183 - 195
• Main Authors: Ryser, Manuel, Künzi, Lisa, Geiser, Marianne, Frenz, Martin, Rička, Jaro
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-03-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Animals; autofluorescence; Biotechnology; Calcium; Calcium - metabolism; Calcium Green-5N; Calibration; cell culture; ciliated airway epithelium; Coloring Agents - metabolism; Culture; Cytosol - metabolism; cytosolic calcium; Endoscopes; Epithelial Cells - cytology; Fiber optics; fiber-optic; Humidity; Hydrogen peroxide; Miniature; Monitoring; online monitoring; Optical Fibers; Optical Imaging - instrumentation; Organic Chemicals - metabolism; ratiometric fluorescence spectroscopy; Swine; Temperature; Trachea - cytology; Calcium Green-5N; ratiometric fluorescence spectroscopy; cell culture; fiber-optic; ciliated airway epithelium; cytosolic calcium; autofluorescence; online monitoring
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.201300089

We present a fluorescence‐lifetime based method for monitoring cell and tissue activity in situ, during cell culturing and in the presence of a strong autofluorescence background. The miniature fiber‐optic probes are easily incorporated in the tight space of a cell culture chamber or in an endoscope. As a first application we monitored the cytosolic calcium levels in porcine tracheal explant cultures using the Calcium Green‐5N (CG5N) indicator. Despite the simplicity of the optical setup we are able to detect changes of calcium concentration as small as 2.5 nM, with a monitoring time resolution of less than 1 s. (© 2013 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
A fluorescence‐lifetime based method for real‐time monitoring of absolute cytosolic calcium concentrations as small as 2.5 nM with a monitoring time resolution of less than 1 s is presented. The key strength of the method is that monitoring can be performed in spite of the presence of strong tissue autofluorescence. This method can directly be adapted for monitoring further important physiological parameters such as pH, nitric oxide and hydrogen peroxide.