Hllow Fiber

Hollow Fiber TFF for Bioprocessing

Hollow Fiber Tangential Flow Filtration (TFF) is a membrane filtration technology used for the separation, concentration and purification of process streams in biotechnology and pharmaceutical applications. Hollow fiber filters can be used for both microfiltration and ultrafiltration and are commonly applied for cell harvesting, clarification, ultrafiltration, diafiltration (UF/DF) and buffer exchange.

In Tangential Flow Filtration, also known as crossflow filtration, the process fluid flows parallel to the membrane surface. Part of the fluid and smaller components pass through the membrane as permeate, while larger components are retained in the retentate.

How Does a Hollow Fiber TFF Filter Work?
A hollow fiber filter consists of a large number of thin, hollow membrane fibers assembled within a module. The process stream flows through the fibers and along the membrane surface. Depending on the selected pore size or Molecular Weight Cut-Off (MWCO), specific components can pass through the membrane while others are retained.

The open and linear flow path of hollow fiber membranes makes this configuration particularly suitable for processes involving cells, biomass and shear-sensitive products.

Selecting the right hollow fiber configuration depends on the specific process. Factors such as membrane type, pore size or MWCO, required membrane area, process flow and the desired separation all play an important role.

Microfiltration with Hollow Fiber TFF
Hollow Fiber TFF can be used for microfiltration. In this process, membranes with relatively larger pore sizes are used to separate cells and larger particles from the liquid phase.

This makes hollow fiber microfiltration suitable for applications such as cell harvesting and clarification. The open channels of hollow fiber modules enable the processing of streams containing biomass.

Ultrafiltration and Diafiltration with Hollow Fiber TFF
In addition to microfiltration, hollow fiber filters are widely used for ultrafiltration and diafiltration, often combined as UF/DF.

During ultrafiltration, the desired product is retained by the membrane while smaller components and liquid pass through as permeate. This allows the product stream to be concentrated.

Diafiltration can subsequently be used to remove smaller dissolved components or change the composition of the process fluid. A common application of diafiltration is buffer exchange.

Selecting the appropriate MWCO is important, as it helps determine which components pass through the membrane and which are retained in the retentate.

Hollow Fiber TFF for Cell Harvesting and Clarification
Cell harvesting and clarification are important applications of Hollow Fiber TFF in bioprocessing.

During these processes, cells, cellular material and other larger components are separated from the liquid phase. Hollow fiber filters can be used for various biological process streams, including processes containing high levels of biomass.

The appropriate hollow fiber configuration depends on factors such as the characteristics of the process stream, biomass concentration, viscosity, required filtration rate and desired separation.

Suitable for Shear-Sensitive Products
Bioprocessing often involves cells, molecules and other biological products that can be sensitive to mechanical stress.

Hollow fiber membranes provide an open and linear flow path, making them suitable for applications where gentle and controlled handling of shear-sensitive products is important.

In addition to membrane selection, process parameters such as flow rate, pressure, module length and membrane area can influence the overall performance of the TFF process.

Single-Use and Reusable Hollow Fiber TFF
Hollow Fiber TFF is available in both single-use and reusable configurations.

Single-use hollow fiber filters can be used when flexibility and reduced cleaning requirements are important. This makes them particularly suitable for bioprocessing environments where single-use technologies are applied.

Cleanable and reusable hollow fiber modules are also available. The most suitable configuration depends on the application, process requirements and production scale.

Scalable Hollow Fiber TFF Solutions
Hollow Fiber TFF can be applied at different scales, from process development to production.

During process development, smaller-scale testing can be used to determine the appropriate membrane configuration, pore size or MWCO and suitable process conditions. The process can then be scaled up using a larger membrane area.

Important parameters for scale-up include membrane area, crossflow, transmembrane pressure (TMP), pressure drop, product concentration and process volume.

Selecting the Right Hollow Fiber TFF Filter
Selecting the right hollow fiber filter depends on the specific application and process conditions. There is no single configuration suitable for every TFF process.

Important factors to consider include:

microfiltration or ultrafiltration;
required pore size or MWCO;
cell harvesting, clarification or UF/DF;
characteristics of the process stream;
presence of cells or biomass;
product sensitivity to shear;
required capacity and membrane area;
process flow and pressure;
single-use or reusable configuration;
required scale and scale-up possibilities.
Van Borselen Filters supports you in selecting and sizing a suitable Hollow Fiber TFF solution for your filtration process.

Frequently Asked Questions About Hollow Fiber TFF
What Is Hollow Fiber TFF?
Hollow Fiber TFF is a form of Tangential Flow Filtration that uses hollow membrane fibers. The process fluid flows along the membrane surface, allowing smaller components to pass through the membrane while larger components are retained. The technology can be used for both microfiltration and ultrafiltration.

What Are Hollow Fiber TFF Filters Used For?
Hollow Fiber TFF filters are used in bioprocessing for applications including cell harvesting, clarification, ultrafiltration, diafiltration (UF/DF), concentration and buffer exchange. The appropriate application depends on the selected membrane and its pore size or MWCO.

What Is the Difference Between Hollow Fiber TFF and TFF Cassettes?
Hollow fiber filters and TFF cassettes both use tangential flow filtration but have different membrane configurations. Hollow fiber modules consist of hollow membrane fibers with an open, linear flow path, while TFF cassettes use flat-sheet membranes in a cassette configuration. The most suitable solution depends on the product, application and process conditions.

How Do I Select the Right Pore Size or MWCO for a Hollow Fiber TFF Filter?
The appropriate pore size or Molecular Weight Cut-Off (MWCO) depends on the required separation. Microfiltration membranes are typically selected based on pore size, while ultrafiltration membranes are commonly specified by MWCO. Product characteristics, process conditions and the desired composition of the retentate and permeate should also be considered.

Can Hollow Fiber TFF Be Scaled Up?
Yes. Hollow Fiber TFF can be applied at different process scales. During scale-up, parameters such as membrane area, crossflow, transmembrane pressure (TMP), pressure drop and product concentration should be considered. This allows a developed TFF process to be transferred to larger process or production scales.

Advice on Hollow Fiber TFF
Are you looking to use Hollow Fiber TFF for microfiltration, ultrafiltration, diafiltration, cell harvesting, clarification or buffer exchange? Van Borselen Filters can help you select a suitable hollow fiber solution based on your process and application.