Viral clearance testing is a critical part of process development and biopharmaceutical production, as it is critical to ensure materials destined for human use are free of viral contaminants. Recent regulatory guidance in the European Union, for instance, has made it necessary to implement viral clearance technologies for the inactivation/removal of an enveloped virus, as well as a small non-enveloped virus. The tests are not cheap, typically costing €150,000 to €200,000 to validate an entire downstream process, and of course must be repeated if the findings don't indicate a suitable log reduction in viral levels is achieved. For that reason some of the larger biotechs have opted to set up their own accredited testing functions. But for many others the only solution is to approach a US Food and Drug Administration (FDA) accredited laboratory such as WuXi AppTec. The other main ones around the globe are operated by BioReliance and Catalent in North America, Newlab Bioquality in Germany and Inveresk in the UK. Sartorius Stedim has set up a unit devoted to analysing viral clearance technologies under non-Good Laboratory Practice (GLP) conditions - effectively serving as a 'pre-testing' service ahead of full GLP trials by an accredited lab. Under the terms of the agreement, WuXi AppTec will provide the relevant viruses, materials and methodologies to Sartorius Stedim, which will use them to test customers' processes and products. Klaus Tarrach, senior product manager of purification technologies at Sartorius Stedim, said in an interview that biotechnology companies are recognising the benefit of carrying out this viral clearance testing earlier and earlier in the development process. "Our testing answers a key question - which is the most appropriate viral clearance technology for each new biopharmaceutical drug?" he said. "Getting an early answer to that can save a lot of money further down the line." "Customers can reliably anticipate - at this very early stage - predictive study results of what might be expected from WuXi AppTec´s GLP viral clearance testing of the same product as part of the Investigational New Drug process and ultimately the Phase III validation process," said Tarrach. Other companies operating in this area are Pall, Millipore and Asahi, but Sartorius Stedim is the only company that manufactures virus clearance systems based on three technologies - 20nm nanofiltration, inactivation by UVC (alongside Bayer Technical Services) and adsorption by membrane chromatography. The agreement with WuXi AppTec gives it an opportunity to encourage adoption of its systems ahead of those of competitors, said Tarrach. However, it will carry out testing on any technology preferred by its clients, he stressed. For Sartorius Stedim the move into non-GLP viral clearance testing as a service is a relatively new one. It has finished construction of its testing unit, and while the facility is up and running the company is in the process of transferring cell lines and viruses into the lab. "We will be able to carry out our first customer tests in the third quarter," said Tarrach.