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.



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. The log net fluorescence is proportional to the log endotoxin concentration and is linear in the 0.005-5.0 EU/ml range.

Advantages of the PyroGene™ rFC Assay:

  • Endotoxin specific, recombinant technology eliminates false-positive glucan reactions
  • Predictable, reliable lot-to-lot assay performance
  • Sustainable resource – no animal utilization
  • Endpoint fluorescent assay, comparable to other quantitative LAL methods
  • 510(K) submissions have been approved by the FDA using PyroGene™ rFC Assay as a final release test
  • Comprehensive FDA Master File

The PyroGene™ rFc Assay 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.