Erik Storm, single-use process engineer at Pall Life Sciences, will speak on single-use system design from the perspective of single-use sensors. Sensors for flow, pressure, pH, and temperature are core components of both single-use and stainless steel bioprocessing. Increasingly, processors are looking into probes for conductivity and ultraviolet absorbance. Fully disposable systems require single-use sensors, so in this respect disposable sensors can be viewed as an enabling technology that should greatly expand single-use through fully functional process containers compliant with the latest FDA quality and risk initiatives.
Rugged, inexpensive sensors have existed for years, and new probes are emerging almost weekly. “It all comes down to what people expect with regard to accuracy, ease of use, and calibration,” Storm notes. Other factors include ease of installation, connectivity, and susceptibility to process conditions for sensors in direct contact with process fluids. Designs for some sensors allow placement on the outside of the process container.
Another significant issue for disposable sensors is where the sensor/container combination is assembled—at the vendor’s site or on-site. Until fairly recently processors assembled their own systems from components purchased from multiple suppliers. This still occurs, but GE’s ReadyCircuits and Sartorius Stedim Biotech’s FlexAct platforms suggest that major suppliers are betting heavily on standardization and/or preassembly, two trends that Pall has long recognized. “Users are looking more and more for integrators to do the assembly for them,” Storm says.
To extend preassembly and standardization to single-use sensors, users will either have to specify the sensor model before ordering the preassembled equipment or vendors like GE, Pall, and Sartorius Stedim Biotech will need to stock a range of standard sensor types.
It turns out that single-use sensors will be well-represented at IBC. One talk, by Lonza Biologics’ senior scientist David Valentine, will compare reusable dissolved oxygen and pH sensors to single-use varieties. Lonza is investigating disposable DO and pH devices for in-line measurements in cGMP fed-batch cell culture processes.
Another talk, by engineer Emmanuelle Cameau of Merck Serono, compares the performances of Finesse Solutions’ TruFluor single-use DO sensor with that of a Mettler-Toledo stainless steel probe. Finally, Philippe-Alexandre Gilbert, Ph.D., senior scientist at MedImmune vaccines, will present data on single-use sensors as they relate to process analytic technology and quality by design.