An in line non-invasive optical system to monitor pH in cell and tissue culture.

pH is an important control parameter for maintenance of cell viability and for improving tissue functions during cell and tissue culture. pH monitoring during cell/tissue culture also provides valuable information on cell metabolic processes and living environment. In this study, an on-line, non-invasive pH monitoring system was developed for use during tissue/cell culture in a perfusion system, using an optical method. This device included light sources, light detectors, light guides and a flow cell. Phenol red was used as a pH indicator dye, and the ratio of light intensities at two wavelengths was measured at the same pH value. Low solution volume as low as around 10 microl could be used to detect pH. Compared to the conventional optical methods, this non-contact optical measurement can avoid the contamination of the tip of optical fibre during the long-term monitoring. It provides a possibility to do on-line monitoring and apply feed back control to maintain the culture environment at the desired conditions required for long-term cell/tissue culture.

[1]  Jill P. G. Urban,et al.  The effect of extracellular pH on matrix turnover by cells of the bovine nucleus pulposus , 2003, European Spine Journal.

[2]  C H Mastrangelo,et al.  Monolithic capillary electrophoresis device with integrated fluorescence detector. , 2001, Analytical chemistry.

[3]  Melody M. Anderson,et al.  Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor. , 2002, Biotechnology and bioengineering.

[4]  A. Manz,et al.  Miniaturized total chemical analysis systems: A novel concept for chemical sensing , 1990 .

[5]  James S. Wilkinson,et al.  Integrated diode detector and optical fibres for in situ detection within micromachined polymerase chain reaction chips , 2001 .

[6]  A Manz,et al.  Novel Instrumentation for Real-Time Monitoring Using Miniaturized Flow Systems with Integrated Biosensors , 1997, Annals of clinical biochemistry.

[7]  Jörg Hübner,et al.  Integrated optical measurement system for fluorescence spectroscopy in microfluidic channels , 2001 .

[8]  P. Greenhalgh,et al.  Simple fibre optic spectrophotometric cell for pH determination. , 1989, Journal of biomedical engineering.

[9]  L. Hall,et al.  Comparison of pH measurements made using 31P NMR and a fibreoptic pH meter , 1992, NMR in biomedicine.

[10]  W. Boron.  Intracellular pH Regulation , 1987 .

[11]  Dimitri Pappas,et al.  Evaluation of the Paratrend Multi-Analyte Sensor for Potential Utilization in Long-Duration Automated Cell Culture Monitoring , 2004, Biomedical microdevices.

[12]  N. Sperelakis,et al.  Cell Physiology Source Book , 1951 .

[13]  P Cleaton-Jones,et al.  A comparison of three electrodes for the measurement of pH in small volumes. , 1997, Caries research.

[14]  J. Møller,et al.  Protein binding of small molecules. II. Role of electrostatic forces for binding of phenol red by human serum albumin. , 1973, Biochimica et biophysica acta.