The gleam of stainless steel is much less in evidence in today’s bioprocessing facilities as disposable aseptic filtration units replace the traditional reusable equipment, according to Michael Labreck, sales manager at Novasep. The company has developed disposable units for tangential flow filtration that are pre-sanitized and prepacked in 0.2M NaOH, ready to use. The modified polysulfone membranes are available in a wide range of molecular weight sizes and are designed for low protein binding.
“The performance of our Sius Single Use TFF cassettes will meet or exceed the performance of traditional, reusable TFF cassettes,” Labreck said. “We have engineered features for additional labor savings and better process economics.”
Michael Xenelis, senior development associate at EMD Serono, reported on his company’s use of Sius TFF disposable units. EMD has replaced the step requiring an anion-exchange column with a membrane, and traditional tangential flow filtration cassettes have been replaced with disposable Sius membranes at the initiation and conclusion of the run.
Replacing the anion-exchange column with a Q membrane generated a myriad of benefits, according to Xenelis, including reduction in buffer usage, set-up time, amount of documentation, and maintenance requirements. The membrane comes ready to use from the box, avoiding laborious column packing, and water saving are significant—60 L of innocuous buffer per run in the disposable situation, as opposed to 350 L in the case of the reusable units.
“The final UF/DF tangential filtration step had previously been the longest and most problematic,” explained Xenelis. “This was a major source of frustration for operators, since flux recovery was poor, buffer demand high, and presumably reusable membranes had to be discarded after a single-use cycle.”
Use of Novasep Sius membranes for tangential flow filtration, Xenelis explained, allowed the elimination of many steps, much attendant time, and resulted in consumables savings. Total process time was cut from 10.4 hours to 5.1 hours, including installation. Additionally, reductions in the protein A column size allowed a savings of $37,000 in protein A resin and buffer costs.
“Through the implementation of the Sius TFF disposable cassettes we were able to reduce costs of buffer, bags, labor, and materials by half or more. For these reasons they are now our standard choice for all new projects.”