Under the terms of the agreement, Agilent will make a payment to Invitrogen, the amount of which was not disclosed. In return, Agilent will stop sale of its RNase H minus reverse transcriptase products. Invitrogen will also take out a license from Agilent for its DNA polymerase blend products and pay royalty fees (also undisclosed). The settlement draws a line under litigation that was originally between Invitrogen and Stratagene, which was acquired in 2007 by Agilent. In June 2000 Invitrogen sued Stratagene in the US district court (Maryland) for the infringement of three patents (US Patent # 6,063,608, 5,244,797, and 5,405,776) involving the sale and use of their RNase H minus reverse RT products (this case had been 'stayed' pending the result of similar litigation against Clontech, which has been ongoing for 11 years). In 2001 a further case was filed relating to a process that Invitrogen had developed for the production of a specially developed efficient form of Escherichia coli cell used for absorbing foreign DNA (US Patent 4,981,797). In 2006 the US District Court for the Western District of Texas, Austin Division, awarded Invitrogen $16.2m and costs but Strategene lodged an appeal, which was still pending. Finally, in November 2001, Stratagen brought a case against Invitrogen, which was for the use and sale of certain DNA polymerase blend products (US Patent 5,556,772) (in this case a reissuance proceeding was pending). Settling the litigation issue will also free up management resources to get on with the ongoing task of driving sales and increasing efficiencies at the company, said Invitrogen CEO Greg Lucier during a conference call on the firm's fourth-quarter results. Revenues for the fourth quarter were $336m and therefore that full year sales were $1.28bn (an 11 per cent increase on 2006). And with margins improving a one percentage point, business seems to be going well for Invitrogen. Sales growth in the fourth quarter was driven mainly by Invitrogen's BioDiscovery segment, which makes products for protein separation, PCR and RNAi, as well as cellular analysis tools. Lucier said drugmakers showed no sign of cutting back on R&D spending, and this was a key factor for Invitrogen's 2007 growth. "R&D spending by pharmaceutical and biotech customers around the world remains very solid with biotech of course growing very strongly." In 2008 the company expects to make big gains in areas such as cell biology, added Lucier, pointing to last year's acquisition of CellzDirect as a key factor in that effort. "Basic research is increasingly focused on the cell as the laboratory where genes, RNA, proteins interact [and] regulatory agencies in both the US and Europe are demanding the use of primary cell models for safety testing." Most laboratories do not have the expertise to develop and optimise culture systems, but the combination of CellzDirect and Invitrogen's other acivities in bioproduction media, specialty cell culture research media, cell separation beads and cell characterisation assays make it well placed to provide assistance in this area. "CellzDirect enables Invitrogen to forge much closer drug discovery and preclinical partnerships with our drug and biotechnology therapeutic customers due to their strength in liver cells," said Lucier.