Charm II Plus Multi-Residue Detection System

Overview

The Charm II Plus Multi-Residue Detection System is a semi-automated, fluorescence-based immuno-receptor assay platform engineered for rapid, reliable screening of multiple chemical and biological contaminants in food and agricultural commodities. Designed and validated by Charm Sciences, Inc. (USA), the system operates on the principle of competitive binding between analytes in the sample and fluorescently labeled ligands for specific receptors—primarily microbial β-lactamase, recombinant receptor proteins, or antibody-conjugated fluorophores—followed by quantification via integrated photometric detection. Its core architecture supports simultaneous qualitative and semi-quantitative assessment across broad classes of regulated substances, including veterinary drug residues, mycotoxins, pesticides, and hygiene indicators (ATP-derived alkaline phosphatase activity). The Charm II Plus is not a chromatographic or mass spectrometric instrument; rather, it delivers regulatory-grade decision support at the front line of quality assurance—enabling pass/fail determinations aligned with Maximum Residue Limits (MRLs) established under Codex Alimentarius, EU Commission Regulations, US FDA Grade A Pasteurized Milk Ordinance (PMO), and China’s GB standards.

Key Features

• Fluorescence immuno-receptor assay technology with built-in optical reader and thermal incubation module
• Semi-automated workflow: manual sample preparation followed by automated reagent dispensing, incubation, and fluorescence measurement
• 10-minute analysis time per sample—optimized for high-throughput laboratory environments and field-deployable QA/QC operations
• Validated against 6 NCIMS/FDA-certified dairy testing methods for β-lactams, tetracyclines, sulfonamides, chloramphenicol, and macrolides
• Integrated data logging: automatic timestamping, sample ID, batch number, operator ID, and result classification (Pass/Fail/Inconclusive)
• Modular test cartridge design—each kit pre-loaded with lyophilized reagents, calibrated controls, and lot-specific calibration curves
• CS2 software compatibility for full audit trail, electronic signature support, and 21 CFR Part 11–compliant data archiving

Sample Compatibility & Compliance

The Charm II Plus accepts liquid and homogenized solid matrices without extensive cleanup: raw and processed bovine milk, whey, cream, infant formula, honey, fish tissue homogenates, poultry muscle, feed extracts, and cereal-based grain slurries. All assays are developed and verified per AOAC Official Method of Analysis (OMA) guidelines and undergo rigorous inter-laboratory validation per ISO/IEC 17025 requirements. Regulatory recognition includes formal inclusion in China’s GB/T 22979–2008 (β-lactams in milk), GB/T 23411–2009 (tetracyclines), and GB/T 32122–2015 (aflatoxin M1); endorsement by Korea’s MFDS and Hong Kong’s Centre for Food Safety; and routine use in EU-accredited dairy control laboratories under Regulation (EC) No 882/2004. The system meets GLP documentation standards and supports GMP-aligned environmental monitoring when deployed for ATP-based hygiene verification.

Software & Data Management

The optional CS2 Data Management Software provides centralized instrument control, real-time result visualization, and structured database storage compliant with FDA 21 CFR Part 11. It enforces role-based access control, electronic signature workflows, and immutable audit logs—including all user actions, calibration events, and result modifications. Raw fluorescence intensity values, calculated % inhibition, and MRL-based interpretation thresholds are stored with metadata traceability to individual test cartridges (including lot numbers and expiration dates). Export formats include CSV, PDF reports, and LIMS-compatible XML, facilitating integration with enterprise laboratory information management systems used in national reference labs and multinational food processors.

Applications

• Routine antibiotic residue screening in raw milk collection centers and dairy processing plants
• Pre-shipment verification of honey and aquaculture products for chloramphenicol and nitrofuran metabolites
• Feed mill QC for tetracycline and sulfonamide carryover in compound feeds
• Regulatory surveillance by CIQ, CDC, and provincial agricultural testing centers for multi-class contaminant profiling
• ATP-based hygiene monitoring of milking equipment, bulk tanks, and processing lines using Charm’s ALP (alkaline phosphatase) assay kits
• Confirmatory triage prior to LC-MS/MS analysis—reducing confirmatory workload by >70% in high-volume dairy labs

FAQ

Is the Charm II Plus suitable for regulatory submission of test results?
Yes—when operated under documented SOPs and maintained per Charm’s service protocol, results generated on the Charm II Plus are accepted by Chinese NIFDC, US FDA, and EU NMKL for official compliance decisions.
Can the system quantify residue concentrations beyond pass/fail thresholds?
It provides semi-quantitative estimates (e.g., “<0.5× MRL”, “1.2× MRL”) based on calibrated inhibition curves—but definitive quantification requires orthogonal confirmation by HPLC-MS/MS.
What maintenance is required to ensure long-term performance stability?
Annual calibration verification using Charm-provided reference standards and quarterly optical path cleaning are recommended; no consumable parts require replacement outside of test cartridges.
Does the system support multi-user network deployment?
Yes—CS2 software enables concurrent access across local area networks with configurable permissions and centralized database hosting.
Are assay kits subject to shelf-life limitations?
All cartridges are lyophilized and stable for 12–24 months refrigerated (2–8°C); each kit includes a printed lot-specific calibration certificate and expiry date.