head uk2

Recombinant factor C assay for detection of bacterial endotoxins in chitosan

Testing for bacterial endotoxins with recombinant factor C might be included as a new general chapter in the European Pharmacopoeia. The European Pharmacopoeia has called for public consultation on the creation of a new General Chapter (2.6.32). In 2016, the Pharm. Eur. referred the rFC test as an alternative to Limulus amebocyte lysate (LAL) in Guidelines for using the test for bacterial endotoxins (Supplement 8.8 Chapter 5.1.10). The next step would be a separate chapter on testing for bacterial endotoxins using the rFC assay.

In the rFC assay, recombinant factor C is activated by endotoxin binding and converts a substrate into its active form, which is quantified by fluorescence photometry. The measured fluorescence signal is directly proportional to the endotoxin concentration of the sample solution.

In comparison, the LAL assay is based on a more complex enzyme cascade, which leads to false-positive results in the presence of ß-glucans by activation of the limulus protein factor G. This is also a problem in the testing of chitosan and chitosan derivatives due to the presence of ß-glucans, which is why the rFC test is a more suitable analysis method for detection of endotoxins in chitosan.

At HMC+, the recombinant factor C assay is an established and validated test method for the detection of bacterial endotoxins for several years. Endotoxins contents below 100 EU/g Chitosan (0.1 EU/mg) can be quantified using the rFC assay.

In addition, the rFC assay is independent of horseshoe crab blood containing the limulus amebocyte lysate for the LAL assay. Since the extraction of lysate depends on the two highly endangered species, Limulus polyphemus and Tachypleus tridentatus, the establishing the rFC assay would be a positive development for the protection of the lysate source and the animal population.


chitosan, rFC, recombinant factor C, endotoxin

Congress and fairs

Meet us in person 2024:

  • 14th PBP World Meeting/ Research Pharm, Vienna, Austria, 18.-21.03.2024
  • CPHI, Milan, Italy, 08.-10.10.2024
  • MEDICA 2024, Düsseldorf, Germany, 11.-14.11.2024

To arrange an appointment please contact Katja Richter via This email address is being protected from spambots. You need JavaScript enabled to view it.


  • Heppe Medical Chitosan GmbH
    Heinrich-Damerow-Strasse 1
    06120 Halle (Saale)
  • Tel.: +49 (0) 345 27 996 300
    Fax: +49 (0) 345 27 996 378
  • This email address is being protected from spambots. You need JavaScript enabled to view it.
Contact | GTC / Terms of Use | Legal info | Copyright © 2024 Heppe Medical Chitosan GmbH | Privacy notice

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.