The newly launched Sartoguard NF prefilter series feature a unique combination of high-performance polyethersulfone (PES) membranes and nanofleece technology. This is said to be the first time that PES nanofleece material is being used for liquid prefiltration applications in biopharmaceutical manufacturing. The nanofleece technology provides an ultrafine fleece structure based on small (120–150-nm dia.) nanofibers compared with conventional fleece materials of more than 500-nm dia. The resulting fleece structure offers enhanced clarification capabilities, even for extremely fine contaminants, along with a high dirt-holding capacity, fast flowrates and high total throughput performance, says the company. — Sartorius Stedim Biotech, Göttingen, Germany and Aubagne, France