Sustainable rFC Endotoxin Assay Kit for Reliable BET - China Suppliers and Factory Certified
Technical Information on Recombinant Factor C (rFC) Fluorometric Assay for Bacterial Endotoxin Detection
The rFC fluorometric assay is a horseshoe crab-free, in vitro method for quantitative bacterial endotoxin (lipopolysaccharide, LPS) detection, compliant with global pharmacopoeias (USP <85>, EP 2.6.14). Its core principle relies on recombinant Factor C (rFC)—a recombinant protein engineered from the LPS-binding domain of horseshoe crab Factor C—eliminating reliance on natural horseshoe crab blood and addressing sustainability concerns.
Endotoxin LPS specifically binds to the LPS-recognition domain of rFC, triggering a conformational change that activates rFC’s serine protease activity. The intensity of AMC fluorescence is directly proportional to the endotoxin concentration in the sample, measurable via a fluorescence microplate reader.
Detects endotoxins at concentrations as low as 0.005 EU/mL, matching or exceeding traditional Limulus Amebocyte Lysate (LAL) assays.
Typically covers 0.005–50 EU/mL, enabling quantitative analysis across a broad concentration spectrum.
Exhibits high specificity for LPS; it is not activated by (1→3)-β-D-glucans, reducing false-positive results.
Requires controlled temperature (37±1°C) and incubation time (60–120 minutes), with detection at ~360 nm/~460 nm.
Prepare samples (e.g., pharmaceuticals, medical devices, biological products) via dilution or extraction to remove matrix interference.
Mix rFC reagent, fluorogenic substrate, and sample in a microplate well.
Incubate at 37°C to allow LPS-rFC binding, activation, and substrate cleavage.
Measure fluorescence intensity; calculate endotoxin concentration using a standard curve generated with known endotoxin standards (e.g., Escherichia coli O55:B5 LPS).
This assay combines sustainability (no horseshoe crab harvesting), reliability (low interference, high reproducibility), and efficiency, making it ideal for quality control in pharmaceutical and biotech industries.
The assay utilizes Recombinant Factor C (rFC) engineered from the horseshoe crab. When endotoxin LPS binds to rFC, it activates its serine protease activity, cleaving a fluorogenic substrate and generating AMC fluorescence proportional to the endotoxin concentration.
The rFC assay can detect endotoxins at concentrations as low as 0.005 EU/mL, which matches or exceeds the sensitivity of traditional Limulus Amebocyte Lysate (LAL) assays.
Yes. The rFC assay has high specificity for LPS and is not activated by (1→3)-β-D-glucans, which are a common source of false-positive interference in traditional LAL gel-clot assays.
The assay requires a controlled incubation temperature of 37±1°C for 60 to 120 minutes. The resulting fluorescence is measured using excitation/emission wavelengths of approximately 360 nm/460 nm.
It is suitable for quality control testing of pharmaceuticals, medical devices, and biological products. Samples are typically prepared via dilution or extraction to eliminate matrix interference before testing.
Because it is an in vitro method that uses a recombinant protein (rFC) rather than natural horseshoe crab blood. This eliminates the need for horseshoe crab harvesting, addressing ecological sustainability concerns.