Recombinant Factor C (rFC)

An animal-free reagent for endotoxin testing that uses Factor C, the first enzyme of the LAL cascade, produced by recombinant technology. When endotoxin activates Factor C, it cleaves a fluorescent substrate, and the signal is measured. rFC avoids harvesting horseshoe crab blood and gives consistent lot-to-lot performance. It is described in Ph. Eur. 2.6.32 and USP. Switching from LAL needs a comparability study for each product.