On-line Biomass Sensors

Risk-based stoichiometric process management, quantitative and qualitative multi-parameter process analysis which permits the gain of more process knowledge and safety as well as for TURBIDOSTAT operational mode and feedback control loop.

On-line measurement of total cell density

The Solida OD-CELL sensor performs online measurement of total cell density in solution. The sensor is based on optical density, which measures the turbidity of the cell suspension. The measurement is made at NIR (near-infrared) wavelengths so it is insensitive to changes in media colour.

All particles and molecules that absorb or scatter light at 880 nm will be detected, including living and dead cells and cell debris. This measurement is effective after inoculation, when cells are expanding quickly but concentrations are low, making permittivity-based readings less reliable.

Simple online measurement of cell growth
Reliable values during the growth phase
Early detection of process deviations

Specifications

  • Sensor length: 120, 225, 325, 425 mm
  • Diameter: 25 or 12 mm
  • Optical path length: 5 mm
  • Wetted parts: 1.4435 stainless steel, sapphire glass, EPDM (FDA approved, USP class VI)
  • O-ring material: EPDM (FDA approved, USP class VI)
  • Steam sterilisable, maximum temperature 135° C
  • Pressure range: 0 – 10 bar (25° C)
  • Measuring range: 0 – 2500, equivalent to total cell density of 0.5 to 100 g/L dry weight
  • Measuring principal: absorbance
  • Wavelength: 880 nm (NIR).

ON-LINE MEASUREMENT OF VIABLE CELL DENSITY

SOLIDA LIVE-CELL sensor enables real-time, online measurement of viable cells in solution. The measurement is not influenced by changes in the media, microcarriers, dead cells, or debris. Online measurement of viable cells makes it possible to detect events and respond in real time without sampling.

  • Increase yield and lower production costs
  • Detect changes in cell physiology with frequency scanning
  • Precisely control harvesting for continuous culturing
  • Early detection of process deviations
  • Sensors optimised for multiple conductivity ranges.

The measurement principle is based on capacitance. In an alternating electrical field, viable cells behave like small capacitors. The charge from these small capacitors is measured by the sensor and reported as permittivity (capacitance per area).

SPECIFICATIONS

  • Process connections: DN25 a-length 70 mm (SG), 46 mm (DG), or 54 mm (DG BE)
    and DN12 a-length 120, 220, 320, 420 mm
  • Wetted parts: 1.4435 stainless steel, PEEK (FDA approved, USP class VI),
  • Platinum, EPDM (FDA approved, USP class VI)
  • O-ring material: EPDM (FDA approved, USP class VI)
  • Steam sterilisable, maximum temperature 135° C
  • Pressure range: 0 – 3 bar (25° C)
  • Measuring range: 0 – 700 pF/cm, equivalent to viable cell density of 5 to 200 g/L dry weight
  • Conductivity range standard: 2 – 50 mS/cm; LC: 0.5 – 10 mS/cm; HC: 5 – 100 mS/cm.