Robust on-line sampling and analysis during long-term perfusion cultivation of mammalian cells.

In an attempt to support robust automated sampling and analysis of mammalian cell bioreactors, an integrated platform, BaychroMA®, was developed which includes an innovative sterile sampling device, automated sample transport, a sample preparation module, online analyzers, and communication interfaces to process automation systems. The robustness of this platform was verified by applying it to a laboratory-scale perfusion bioreactor that was operated for over 100 days. Both manual and automated samples were collected over the course of the run and a comparison was made for cell density, viability, glucose, and lactate concentrations.

Extending the narrow-bandwidth tunability of a thin disk Yb:YAG laser regenerative amplifier.

We investigate the characteristics of a thin disk laser system based on the master oscillator-power amplifier design. The amplifier emits parasitic laser oscillation (PL) when the wavelength of the tunable narrow-bandwidth seed pulse is detuned more than 4 nm from the gain maximum at 1030 nm. For suppression of this unwanted PL, a birefringent filter (Lyot filter) was inserted into the amplifier cavity in order to generate wavelength selective losses, especially at the gain maximum of the Yb:YAG crystal.