By Matthew Zustiak, Director, BCC; Mark Thomas Smith, Sr. Manager, Research & Development; Qingwei Luo, Manager, Process Development; Jon Kruger, Engineer I, Systems Design; Wesley Aaron Dryden, Bio Engineer; and Michelle Nolasco Rivera, Supervisor, Systems Design Engineering, Thermo Fisher Scientific
Clarification of Chinese hamster ovary (CHO) cell cultures has long been a challenge for the bioprocessing community, particularly in single-use technology (SUT) formats. Until recently, multi-stage depth filtration has been the preferred solution in single-use (SU) bioprocessing. Accepted alternative solutions have allowed bioprocess engineers to overlook the many challenges of depth filtration, such as:
- High levels of leachables requiring wastefully large filter flushing volumes of WFI (e.g., 100 L/m2)
- Lack of predictable scalability due to process variations, lot-to-lot variation, and varying geometry of scale-down of depth filters, requiring substantial and costly oversizing safety factors on scale-up (e.g., 50% overage)
- Process development optimization needed because of the multi-stage nature of a 2-filter system (crude and fine) either requiring large, costly optimization studies or effectively ensuring suboptimal use
- Inconsistent supply assurance due in part to the increasing use of SUT generally and difficulty of ramping up production of filters
- Limited ease of use caused in large part by the number of filters to be shipped, stored, dispositioned, installed, and disposed of, which might be >60 cassettes for a 2,000 L harvest
Here, we present data comparing the performance of the 3M Harvest RC system to an industry-standard 2-stage depth filtration train. Areas tested were cell density, scalability, and increased product recovery yields. Based on the performance data, we evaluated how the harvest options compared at 2,000 and 5,000 L scales and reviewed the facility-fit feasibility and sustainability. Overall, the 3M Harvest RC system offers a promising solution to the continual challenges caused by traditional SU depth filtration.