In the latest suit, Pall alleges that the Impact filter cartridge line infringes four patents that relate to its Ultipleat filter pack and EZD filter capsule. The company is seeking damages from Entegris as well as an injunction to stop the firm from selling the Impact line. According to Pall, the filter cartridges are used in a variety of process applications within the pharmaceutical industry where enhanced performance and lower processing costs are needed. The laid-over pleat design used in the Ultipleat line allows more filter material to be packed into a smaller cartridge, while enabling a 30 per cent increase in effective filtration area. The company supplies the line with a range of filter packings, including the Supor EKV which allows the sterile filtration of a wide range of fluids including buffers, biological fluids and tissue culture media. The low protein binding of the Supor membrane ensures the maximum transmission of active ingredients, which is very important when filtrates such as recombinant Factor VIII carry a price of several hundred thousand dollars per gram. "Our patents are core assets. They represent countless hours of work by our scientists and engineers and millions of dollars of corporate resources. We vigorously protect our intellectual property rights," said Steve Chisolm, president of Pall Microelectronics. In April 2006, Entegris filed a lawsuit against Pall claiming that the company's PhotoKleen EZD-3 filter assembly infringes a patent that was granted to Entegris earlier that month. That patent is a continuation of a prior patent owned by Entegris that which the two companies were disputing. In January 2005, a US District Court ruled that the earlier patent was likely to be invalid. In March 2006, the European Patent Office (EPO) revoked a patent with claims similar to the April 2006 patent. Entegris also claims that Pall's PhotoKleen EZD-2 filter assembly and EZD-3 retrofit products infringe on other patents that it owns. In 2005, Pall filed a separate action claiming that Entegris' Quickchange and Waferguard products infringe on two other Pall patents that is still ongoing.