Broader Range, Non-invasive pH Monitoring

Self-adhesive pH Sensor Spots SP-LG1-SA

These new pH Sensor Spots cover a broader measurement range from pH 4.0 to 7.5, and are therefore optimally suited for bioprocess development, pharmaceutical applications and different fields of research. Due to their optical isolation and the optimized spectral properties the pH sensor spots are less sensitive to interfering fluorescences. The self-adhesive technology eases integration of the SP-LG1-SA in transparent glass or plastic vessels. They can simply be stuck on the inside surface and measurements can be taken non-invasively from the outside through the vessel wall. These sensor spots are available irradiated or untreated. They come pre-calibrated and ready-to-use.

  • Non-invasive, online pH measurements from pH 4.0 to 7.5
  • No electrical interferences due to optical measurements
  • No assembly necessary, ready-to-use
  • No electrolyte to replenish
  • Pre-calibrated, one-point calibration possible
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Bioprocess Development: pH Monitoring in Shake Flasks

The pH is one of the major issues in the cultivation of cells, yeast or bacteria. Shake flask cultures are widely applied in academic and industrial bioprocess development. As adequate methods for real monitoring of pH were not available, cumbersome at-line sampling was used. The combination with non-invasive oxygen sensors in shake flasks provides new insights into metabolic activity and changes in metabolic pathways.


*provided pH sensors are used without further handling in physiological solution
**calibration and following measurements in the same conditions / system; equilibrated sensor kept in well stirred solution at + 37 °C
Measurement range 4.0 - 7.5 pH
Resolution at pH = 6.5: ± 0.01 pH
Drift at pH = 6: < 0.005 pH per day (sampling interval of 1 min.)
Measurement temperature range from + 5 °C to + 50 °C
Response time (t90)** < 120 sec.
Compatibility Aqueous solutions, ethanol (max. 10 % v/v), methanol (max. 10 % v/v), pH 2 - 10
Cross-sensitivity Reduced ionic strength (salinity); a high concentration of small fluorescent molecules in the visible range can interfere
Cleaning procedure pH spots are delivered either beta-irradiated or untreated, a second irradiation or ethylene oxide treatment is not recommended
Calibration pH spots are pre-calibrated; re-calibration is possible
Carrier materials Adhers to nearly all surfaces like glass, polystyrene, polyethylene, polymethacrylate (acrylic glass), polycarbonate. The sensor does NOT adhere to silicone surfaces!

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