
The Lonza PyroGene ® Recombinant Factor C (rFC) Endotoxin Detection Assay is an alternative to the traditional limulus amebocyte lysate (LAL) assay, which is widely used to screen for bacterial endotoxin contamination in human and animal parenteral pharmaceuticals and medical devices. The rFC test is used in both high and low throughput laboratories and, unlike the LAL assay, it is not derived from horseshoe crab blood. Setting up the test requires manual preparation of 10-fold diluted standards from the endotoxin stock solution supplied. Standards and samples are added in duplicate wells to a 96 well plate. To check for product inhibition, positive product controls (PPCs), which are samples spiked with a known concentration of endotoxin, are tested alongside samples. Following the initial plating of the standards, samples and PPCs, a 10-minute pre-incubation is performed, during which the user prepares a working solution that consists of the fluorogenic substrate, assay buffer and rFC enzyme.
This application note demonstrates that the preparation of the standards, samples, PPC samples and blanks, and their addition to the 96 well plate, can be easily automated on the ASSIST PLUS pipetting robot using a D-ONE single channel pipetting module. Addition of the working reagent is then completed using the VOYAGER adjustable tip spacing multichannel pipette. Automation of all the pipetting steps reduces the opportunity for pipetting errors, and ensures robust reproducibility. The key quality indicators in this assay are the correlation coefficient of the standard curve and coefficient of sample variation (CV).