Choosing an endotoxin method in the recombinant era

Sponsored by Charles River Laboratories2026-09-28T12:37:00

Recombinant technologies are reshaping endotoxin testing, offering alternatives to horseshoe crab-derived reagents while maintaining pharmaceutical quality standards.

Microbial quality control is a critical component of pharmaceutical manufacturing, supporting the safety and efficacy of drug products without being visible to patients. However, increasing attention is being placed on the use of horseshoe crabs in this process, particularly in relation to injectable medicines. Having supported pharmaceutical quality assurance for more than 40 years, the species is now at the intersection of advances in testing technology, environmental sustainability and growing expectations around corporate responsibility.

Recombinant technology has also opened the way to alternatives to traditional endotoxin testing. Introduced in the early 2000s, recombinant Factor C (rFC) assays produce Factor C in the laboratory, enabling endotoxin detection without relying on horseshoe crab-derived reagents.

This article follows the journey of endotoxin testing, from the first Limulus amoebocyte lysate (LAL) test to the recombinant options that are in use today and takes stock of where the guidelines now stand.