Single-use tangential flow filtration (TFF) technology offers a range of benefits in ultrafiltration and microfiltration applications in bioprocessing.
While manufacturers have to fit a process around more traditional stainless steel equipment, single-use TFF can be easily modified. This makes the technology very flexible and of particular benefit to contract manufacturing organizations (CMOs) or multi-product facilities.
A typical single-use TFF set-up is comprised of filters, an agitated retentate container with balance, tubing, a peristaltic or diaphragm pump, sensors and a range of software and hardware. All the components that come into contact with a fluid are disposable, which eliminates the need for expensive cleaning utilities, reduces the risk of product contaminations and lowers up-front capital expenditure.
In a poll conducted during a recent Parker domnick hunter webinar, 47% of respondents revealed that they are planning their approach to single-use TFF (n=81), which indicated that the benefits are beginning to be recognized in the industry. Even more encouraging was that 12% were already operating single-use TFF into their process.
Filter selection and sizing
When choosing a filter for your process, there are a number of membranes available and the selection will depend on the characteristics of the molecules you want to retain.
At Parker domnick hunter we believe that modified polyethersulphone (mPES) is the most effective membrane material for cross-flow filtration applications due to its extremely low binding characteristics. The size and scale of a membrane will depend on the average permeate flux at a specified transmembrane pressure (TMP), which is determined through small-scale laboratory experiments, as well as the volume of permeate that will be generated at the large-scale and the required processing time.
PROPOR TFF single-use hollow fibre filters feature robust, 100% integrity tested mPES membrane which prevents fouling and maximizes throughput, lifetime and yields. The extremely narrow porosity specification minimizes bioprocess variability so that product consistency is maintained batch to batch and when scaling up from R & D to manufacturing.
While hollow fibre filters are common in microfiltration applications, cassettes have been traditionally employed in ultrafiltration applications such as protein or vaccine concentration and diafiltration. However, there are several benefits to using hollow fibre filter formats over cassettes in ultrafiltration applications, especially in cost and time savings.
In our second webinar poll, 78% of the audience believed TFF hollow fibres would be a viable option for ultrafiltration applications in their processes (n=87), which confirms our belief that they have a future in downstream bioprocessing.
Controlling TFF operations in bioprocessing
In terms of TFF control methods, there are a number of strategies that can be adopted to maintain cross-flow rate and pressure.
With an ultrafiltration application, you can utilize a proportional valve on the retentate line to maximize and maintain flux rate. For a microfiltration application, you can locate a pump on the permeate line which minimizes gel layer formation by controlling the permeate flow rate and maximizing the cross flow effect.
What is important, according to our final webinar poll, is that flexibility (42%) and simplicity (38%) are maintained when controlling a single-use TFF step (n=82).
View our webinar – Best Practices for Developing Single-Use TFF Steps – on demand.
What do you think? Do you agree with the webinar poll respondents? Let us know in the comments section below.
Parker domnick hunter, specializes in automating and controlling single-use processes. By integrating sensory and automation technology into a process, a manufacturer can control the fluid flow more effectively, ensuring the quality of the final product. Find out more about Parker domnick hunter's single-use TFF solutions.
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