Description

The bacterial endotoxin test (BET) is an essential component of pharmaceutical quality control (QC), as endotoxins can trigger strong immune responses in humans and animals even at trace levels. Conventional testing methods based on Limulus Amebocyte Lysate (LAL) depend on harvesting horseshoe crabs, raising sustainability concerns, and are subject to challenges such as cross-reactivity and lot-to-lot variability.

In May 2025, the United States Pharmacopeia (USP) introduced new chapters permitting recombinant reagents (rCR, rFC) for endotoxin detection. Building on this regulatory milestone, SHENTEK® Recombinant Cascade Reagent (rCR) offers a reliable, eco-sustainable alternative to LAL-based assays. This recombinant reagent ensures improved batch-to-batch consistency, robust quality control, and enhanced safety assurance for pharmaceutical testing applications.

Overview

The SHENTEK® Recombinant Cascade Reagent (rCR) is a recombinant endotoxin detection system based on a cascade enzyme reaction synthesized by recombinant expression. It mimics the reaction mechanism of natural Tachypleus amebocyte lysate by specifically recognizing endotoxins. The kit contains recombinant Factor C, recombinant Factor B, and recombinant proclotting enzyme, enabling sensitive and quantitative detection of endotoxins from Gram-negative bacteria in test samples.

Unlike natural lysate, this recombinant system does not contain the G factor, effectively eliminating interference from β-D-glucan and other LAL-reactive substances. This ensures higher specificity and reliability compared to conventional LAL assays.

This product is suitable for quantitative endotoxin detection in human and veterinary injectable drugs, biological products, and medical devices.

Applications

Injectable drugs for human and veterinary use – including chemical drugs, radiopharmaceuticals, antibiotics, and biological products.
Medical devices – testing of raw materials, auxiliary materials, intermediates, and finished products (e.g., dialysates, implantable devices).

Introduction

Components	Shipping Condition	Unit Size	Detection Method
Recombinant cascade reagent A	2-8℃	96 Tests	Recombinant Cascade
Recombinant cascade reagent B
Recombinant cascade buffer
96-well Microplate
Water for BET

Features

Linearity & Range	0.005 EU/mL to 5 EU/mL
Reduced False Positives	Free of G-Factor, effectively eliminating interference from β-D-glucan and LAL-reactive substances.
Rapid Detection	Results available within 60 minutes.
Regulatory Compliance	USP <85>, FDA BET guidance, ICH Q6B
3R-Aligned	Supports Replace, Reduce, Refine in testing
Proven Performance	Equivalent to gel-clot, KTA, and chromogenic methods
High Consistency	Recombinant production ensures lot-to-lot reproducibility
Animal-Free	Eco-friendly alternative to traditional LAL

Equivalence in Endotoxin Detection: Recombinant Cascade Reagent vs. LAL Reagent

Sample	Recombinant Cascade Reagent			LAL Reagent
Sample	Average Detection Value (EU/mL)	Spike Recovery (%)	CV after Spiking (%)	Average Detection Value (EU/mL)	Spike Recovery (%)	CV after Spiking (%)
Cell Culture Supplement	<0.005	122.6	4.493	<0.005	101	2.789
300 g/L Glucose	<0.005	70	4.199	<0.005	82.2	1.774
FBS	<0.005	110.4	4.284	<0.005	96	4.284
Medium	<0.005	114	0.549	<0.005	123.2	1.07
Cell Culture Supernatant	<0.005	95.4	2.175	<0.005	152.4	12.348
Live Attenuated Hepatitis A Vaccine	<0.005	96.6	0.524	<0.005	123.6	2.732
mAb A	0.026	175.4	2.181	0.034	156.6	0.908
mAb B	<0.005	139	0.579	<0.005	130.8	2.02
0.1% BSA	<0.005	92.4	14.716	0.009	89.8	0.923

Superior Anti-Interference Capability

Test Sample	MVD (λ=0.005EU/mL)	Non-Interfering Dilution (NID)		Spike Recovery (%)
Test Sample	MVD (λ=0.005EU/mL)	Recombinant Cascade Reagent (rCR)	Recombinant Factor C (rFC)	Recombinant Cascade Reagent (rCR)	Recombinant Factor C (rFC)
Cell Culture Supplement (Pink)	100	2	16	1226	79
Emulsifier (Milky White)	1000	40	640	110.4	151.8
Cell Culture Supernatant (with Phenol Red)	200	1	200	95.4	126.8
mAb A (High Protein)	200	1	2	175.4	135.4
Saline for Injection (High Salt)	50	16	2	89.6	116.8

For Research Use Only. Not intended for clinical use.

Recombinant Cascade Reagent (rCR) (Kinetic-Chromogenic Assay) SHENTEK®