Free Sample for Recombinant Factor C Endotoxin Detection Kit (RES-A056)

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Endotoxin testing is crucial for drug production quality control, directly affecting the safety and effectiveness of pharmaceuticals. Traditional Limulus Amebocyte Lysate (LAL) testing has been widely used but has limitations. LAL reagents are derived from horseshoe crab blood, and large-scale harvesting threatens their populations. Additionally, batch-to-batch variability in LAL reagents can impact test accuracy and consistency.

Advancements in recombinant protein technology have led to the development of the recombinant Factor C (rFC) testing method. This method offers a more sustainable and efficient alternative to traditional LAL testing. As the standards for rFC endotoxin testing evolve, it is being adopted by pharmacopoeias worldwide, positioning rFC to become the mainstream method for endotoxin detection, which is crucial for drug safety and industry progress.

Global Pharmacopoeia Status

• European Pharmacopoeia: Europe has been a leader in developing recombinant Factor C testing standards. In 2015, the European Pharmacopoeia recognized recombinant Factor C as an alternative method. By 2017, work began on the development of this method, and in January 2021, Chapter 2.6.32 was officially released, outlining bacterial endotoxin testing using recombinant Factor C. This method is now widely adopted across Europe, and in 2020, recombinant Factor C-based endotoxin testing was approved for drug release.

• United States Pharmacopeia (USP): The research and standardization of recombinant Factor C testing are ongoing in the United States. A 2018 draft included recombinant Factor C as an accepted alternative method, with further revisions made to the standards. On July 26, 2024, the USP Microbiology Expert Committee approved Chapter<86>: Bacterial Endotoxin Testing, which permits the use of recombinant Factor C (rFC) for endotoxin testing. The final text will be published in November 2024 and come into effect in May 2025.

• Japanese Pharmacopoeia: Japan has been actively conducting related research. Its expert committee-initiated discussions on developing a bacterial endotoxin testing method using recombinant Factor C and conducted comparative studies between horseshoe crab reagents and recombinant Factor C. The relevant section,, outlines procedures and considerations for endotoxin testing with recombinant protein reagents.

Limitations of the LAL Reagent Testing Method

1. Susceptibility to Product Interference: Certain products can interfere with the LAL reagent’s reaction to endotoxins. Chemical interferences, such as fluorescence affecting protein denaturation, and pH levels outside the 6.0-7.5 range, can cause issues. Physical interferences, such as endotoxin adsorption and product viscosity, may also impact results. Furthermore, the type and shape of glassware used in gel-based methods can influence test effectiveness, with siliconized glassware and plastics inhibiting gel formation or disrupting spectrophotometric readings.

2. Limited Applicability: Turbidity and colorimetric methods cannot be used for turbid or colored products. Precipitate formation can interfere with testing and potentially lead to false positives. In colorimetric assays, precipitates may form after acid is added to terminate the reaction, especially in products that only dissolve in neutral or alkaline pH conditions.

3. Result Variability: The reliability and accuracy of LAL testing must be validated for each product. The source of LAL reagents can introduce variability, so any change in reagent source requires re-validation, which increases testing complexity and costs.

Advantages and Future Prospects of the rFC Method

Traditional LAL reagents rely on horseshoe crab blood, which harms crab populations and causes quality issues. As a result, pharmacopoeias worldwide are promoting non-animal-based testing methods. The recombinant Factor C (rFC) method uses recombinant DNA technology to produce Factor C, offering better reliability and control while avoiding the interference and false positives seen with LAL reagents. The rFC method provides improved sensitivity and specificity, and is capable of testing complex samples, ensuring the safety of high-risk products like biologics and gene therapies. As technology advances, rFC is set to strengthen pharmaceutical quality control, drive industry growth, and ensure drug safety.

Validation Data

The kit demonstrates outstanding buffer compatibility, working with a wide range of buffer systems.

We have conducted interference effect tests about different ionic strengths, different pH buffers, and different mediums, the kit has excellent buffer compatibility. For specific buffers or mediums, it is recommended that you verify recovery to determine the minimum dilution ratio.

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Upcoming Endotoxin Detection Insights Series:

•  Part 1: Strategies for Mitigating β-Glucan Interference in Endotoxin Detection

•  Part 2: Application of Recombinant Factor C Endotoxin Testing in Pharmaceutical Manufacturing

•  Part 3: Comparison of Recombinant Factor C and Other LAL Methods

•  Part 4: A Comprehensive Guide to Sample Dilution Calculations for Recombinant Factor C Endotoxin Testing

•  Part 5: Key Considerations for Endotoxin Testing Experimental Procedures

•  Part 6: Interfering Factors in Endotoxin Testing

•  Part 7: Endotoxin Detection Standards and Guidelines from a Pharmacopeial Perspective