With the continuous advancement of upstream cell culture processes in the biotechnology industry, the expression levels of target proteins are increasing, leading to higher cell densities in production. Consequently, the impurity content in cell fermentation broth, such as cell debris, HCP, and HCD, is also on the rise, posing greater challenges to traditional depth filters that use diatomite as the filter media.

The most prominent issue with traditional depth filters is their low throughput capacity and limited impurity removal capability. Moreover, the filter aid used in traditional depth filters is natural diatomite, which requires extensive washing before use to minimize leaching and precipitation. In response to market demand, Cobetter has launched the SP series of composite fiber depth filters, which offer lower WFI flushing requirements, higher throughput capacity, and improved impurity removal capability compared to traditional depth filters.

Traditional Depth Filtration Products

Traditional depth filtration products use natural cellulose as the framework and filter aids such as diatomite as the filtration medium. With the use of ion-type binders, suspended solids in the fluid are randomly adsorbed or trapped in these pores when passing through the filtration medium.

Figure 1: Traditional depth filtration

Cobetter New Product: SP-Series Depth Filters

By using composite fiber materials as the framework, a tight three-dimensional structure is formed without β-glucan interference. Synthetic silica is used as the filter aid, creating a larger specific surface area internally to enhance dirt-holding capacity. The combination of these materials provides excellent mechanical properties, lower leaching and precipitation, higher throughput capacity, and superior clarification performance.

Figure 2: SEM images of cellulose

Advantages of Cobetter SP-Series Depth Filters

1. Lower WFI rinsing requirements

Conventional diatomite depth filters require: A total water flushing volume of ≥100L/m².

SP series depth filters require: A total water flushing volume of ≥50L/m².

Figure 3,4: Comparison of water flushing requirements between conventional PC type and new SP type depth filters

2. Higher throughput capacity

Solution Information: CHO cell-expressed monoclonal antibody product, live cell density of 30×10⁶ cells/mL, cell viability of 97%, initial turbidity: 2030 NTU. Test results are as follows:

Figure 5: 4070 PC vs 4070 SP

Cobetter SP-Series Depth Filter Models

If you have such application needs, welcome to contact us for inquiries and to obtain test samples.