Detection Method

Kinetic chromogenic assay

Assay Time

60 minutes

Storage Temperature

2-8 °C (stable for 12 months)

Product Description

The EndoSynX™ Recombinant Cascade Reagent (rCR) is a recombinant endotoxin detection system that mimics the enzymatic cascade of natural Limulus Polyphemus Lysate. The reagent formulation contains Recombinant Factor C, Recombinant Factor B, and Recombinant Proclotting Enzyme. Upon exposure to Gram-negative bacterial endotoxin (lipopolysaccharide, LPS), Recombinant Factor C is activated and initiates a serine protease cascade producing a kinetic chromogenic signal proportional to endotoxin concentration. The EndoSynX rCR does NOT contain Factor G, eliminating interference from β-D-glucan and other LAL-reactive materials. The kit is intended for quantitative determination of endotoxin in pharmaceutical products and research applications. For Research Use Only (RUO) — not for clinical diagnostic use.

Technical Specifications

Parameter	Details
Sensitivity / Assay Range	0.005 - 5 EU/mL (recommended standard curve range)
Lowest standard (λ)	0.005 EU/mL (lowest concentration used in standard curve)
Limit of detection (LOD)	Lowest measurable standard is 0.005 EU/mL (use as LOD reference for assay validation)
Package size / Total reactions	96 tests / kit (2 × 96-well microplates included)
Shelf life	12 months at 2-8 °C (see product labels for expiry)
Storage	Store kit components at 2-8 °C
Instrument / Read settings	Incubating kinetic microplate reader at 37 °C; wavelength 405 nm; reading time 60 minutes; reading interval 30–60 seconds; onset OD 0.02–0.1; shaking before read: medium speed 5–10 s
Maximum Valid Dilution (MVD)	MVD = (endotoxin limit × concentration of sample solution) / λ; λ = 0.005 EU/mL (example: for antibody drugs with endotoxin limit 0.1 EU/mg and sample 10 mg/mL, MVD = 1:200)
Standard curve acceptance	Correlation coefficient (absolute) ≥ 0.980 for standard curve (Solution C)
Spike recovery acceptance	Measured recovery of added endotoxin after subtraction must be within 50%–200% to be considered free of assay-interfering factors under test conditions
Sample pH requirement	Sample pH must be between 6.0 and 8.0

Features

Recombinant cascade (Factor C-based): Uses recombinant Factor C, Factor B and Proclotting Enzyme to replicate LAL enzymatic cascade without animal-derived lysate.
No Factor G (reduced glucan interference): Does not contain Factor G, eliminating interference from β-D-glucan and other LAL-reactive materials.
Kinetic chromogenic readout: Kinetic-colorimetric (chromogenic) signal correlates with endotoxin concentration enabling quantitative measurement.
96-well plate format: Supplied with 96-well microplates (2 plates) for high-throughput testing; kit provides Water for BET and buffers for assay setup.
Designed for pharmaceutical testing: Suitable for quantitative determination of endotoxin in drug substances, drug products and biologics (research/QC applications).

Applications

Quantitative endotoxin testing of pharmaceutical products (drug substances and drug products)
Endotoxin testing of biologics, antibodies and vaccines (research and QC)
In-process testing and batch release support in R&D laboratories
Research use in laboratories assessing endotoxin contamination and formulation suitability

Kit Contents

Recombinant Cascade Reagent A (PNR018), 4 vials2-8 °C

Recombinant Cascade Reagent B (PNR019), 4 vials2-8 °C

Recombinant Cascade Buffer (PNR016), 2.5 mL × 2 vials2-8 °C

96-well Microplate, 2 platesStore as instructed on label (2-8 °C recommended)

Water for BET (NND072), 8 mL × 4 vials2-8 °C

* Total: 96 tests/Kit | Method: Kinetic chromogenic assay (Recombinant Factor C cascade)

Attention

• For Bacterial Endotoxins Tests only; not for clinical diagnostic use (Research Use Only).

• Use sterile, pyrogen-free consumables (pipette tips, tubes, reservoirs) and prevent contamination.

• Sample pH must be between 6.0–8.0 prior to testing.

• Discard dissolved Recombinant Cascade Reagent A if the solution turns yellow or insoluble material appears.

• Equilibrate reagent vials to room temperature before use; avoid vigorous shaking (mix by gentle inversion).

• Dispensing of Reaction Mixture Solution into the 96-well plate must be completed within 5 minutes to ensure assay accuracy.

• Each assay must include appropriate controls: standard curve (0.005–5 EU/mL recommended), negative control (Water for BET), and positive product control (PPC).

• Users must verify the method is appropriate for their specific product/material (perform interference/inhibition tests and follow Verification of Compendial Procedures <1226>).

Quality Management & Certifications

Quality System

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QMS (ISO, GMP)

Download Certificate

Quality Advantages

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Quality Control Process

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📂 Technical Resources & Downloads

PDF Product Manual ↓ PDF MSDS / SDS ↓

Frequently Asked Questions (FAQ)

Q1: What is the working assay range and lowest detectable concentration?

The recommended standard curve range is 0.005–5 EU/mL. The lowest standard (λ) provided is 0.005 EU/mL and should be used as the reference for sensitivity and MVD calculations.

Q2: How should I prepare and run the assay on a microplate reader?

Use an incubating kinetic microplate reader set to 37 °C, measure at 405 nm, run kinetic reads for 60 minutes with read intervals of 30–60 seconds and an onset OD of 0.02–0.1. Prepare reaction mix as instructed (Buffer → rCR-A → rCR-B) and add 100 µL per well; insert plate immediately and start reading.

Q3: How do I check for interference from my sample matrix?

Perform an inhibition/enhancement test using Solutions A–D as described in the manual: spike sample at a midpoint concentration of the standard curve, include standard curve and water controls. Recovery of added endotoxin must be within 50%–200% after subtraction of background to be considered free of interfering factors.

Q4: What storage conditions and shelf life apply to the kit?

Store the kit at 2–8 °C. The stated shelf life is 12 months at 2–8 °C; always check product labels for expiry dates.

Research Use Only

✔

Research Use Only (RUO). Method and use aligned with USP <85>, USP <86> (recombinant reagents) and Ph. Eur. <2.6.14>. Not for clinical diagnostic use. – This product is intended for laboratory research purposes only and not for clinical or regulatory diagnostic use.

✔

Not intended for use in USDA or FDA regulated diagnostic testing or official compliance testing.

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