The PyroGene™ Recombinant Factor C Assay is the evolution of endotoxin detection testing. Lonza scientists have developed a recombinant form of Factor C, the first component in the horseshoe crab clotting cascade activated by endotoxin. Recombinant Factor C (rFC) is activated by endotoxin binding, and the active enzyme then cleaves a synthetic substrate, resulting in the generation of a fluorogenic compound. PyroGene™ rFC works through a single enzymatic step compared to the multiple step enzymatic process necessary for LAL assays.The reaction is run in a 96-well microplate and is measured at time zero and after a one-hour incubation in a fluorescent microplate reader using excitation/emission wavelengths of 380/440 nm. In the presence of endotoxin, activated rFC will cleave the fluorogenic substrate, causing the solution to fluoresce. The log net fluorescence is proportional to the log endotoxin concentration and is linear in the 0.005 - 5.0 EU/ml range.The PyroGene™ rFcAssay is equivalent to other photometric endotoxin methods that use LAL to detect endotoxins according to the parameters listed in the USP chapter<<1225>> “Validation of Compedial Procedures”. These parameters include linearity, specificity, precision, accuracy, and limit of detection.Lonza and the PyroGene™ rFC Assay are leading the way through the evolution of endotoxin detection.