CHARM II 7600 Multi-Residue Screening System

Overview

The CHARM II 7600 Multi-Residue Screening System is a dual-channel, fluorescence-based immuno-receptor assay platform engineered for rapid, reliable qualitative and semi-quantitative detection of veterinary drug residues, mycotoxins, pesticides, and hygiene indicators in food and agricultural commodities. Built upon the well-established Charm II technology—originally developed by Charm Sciences, Inc. (USA)—the system utilizes competitive binding immunoassays where analyte-specific receptors (e.g., antibodies or receptor proteins) are labeled with fluorescent tracers. Upon sample extraction and incubation, target residues displace the tracer from immobilized receptors; signal intensity inversely correlates with analyte concentration. This principle enables high-specificity screening across diverse chemical classes without chromatographic separation, making it ideal for high-throughput regulatory surveillance and in-process quality control.

Key Features

• Dual-channel optical detection architecture enables parallel analysis of two independent samples or internal controls, improving workflow efficiency and result verification.
• Integrated 300–680 nm excitation/emission spectral range supports broad compatibility with industry-standard fluorescent labels including Eu-chelates, FITC, and other common immunoassay fluorophores.
• Automated calibration and on-board reference standards ensure consistent instrument performance across shifts and operators.
• Rugged benchtop design meets ISO/IEC 17025 laboratory environmental requirements; no external PC required for basic operation—embedded touchscreen interface guides users through assay setup, timing, and result interpretation.
• Pre-validated assay protocols aligned with AOAC Official Methods of Analysis (OMA), USDA-FSIS directives, and European Commission Regulation (EU) No 519/2013 for residue monitoring.

Sample Compatibility & Compliance

The CHARM II 7600 accommodates liquid extracts and clarified homogenates from raw and processed matrices including bovine milk, honey, muscle tissue, fish fillets, eggs, cereals, feedstuffs, and environmental swabs. Sample preparation follows standardized extraction procedures defined in FDA’s Bacteriological Analytical Manual (BAM) Chapter 14 and ISO 18593 for surface hygiene testing. All validated assays comply with GLP-aligned documentation practices and support full audit trails for 21 CFR Part 11–compliant data integrity when integrated with optional LIMS connectivity. Method equivalence to national standards—including China’s GB/T 22978–2008 (β-lactams in milk) and GB/T 23202–2008 (aflatoxin M1)—has been formally recognized by CNAS-accredited laboratories.

Software & Data Management

The system runs proprietary firmware v4.2+ with embedded database storage for ≥5,000 test records, each timestamped and user-ID logged. Export options include CSV and PDF reports compliant with ISO/IEC 17025 record retention requirements. Optional USB or Ethernet connectivity enables secure transfer to enterprise LIMS or ELN systems. Audit trail functionality captures all critical events: assay initiation, reagent lot entry, result flagging, and manual overrides—with immutable timestamps and operator authentication. Software validation packages (IQ/OQ/PQ documentation) are available for GMP-regulated facilities requiring formal system qualification.

Applications

• Regulatory screening: Routine surveillance of β-lactams, tetracyclines, sulfonamides, chloramphenicol, macrolides, lincosamides, aminoglycosides, and novobiocin in raw milk and dairy products.
• Mycotoxin control: Aflatoxin M1 quantification in milk and aflatoxin B1 in grains at levels aligned with EU maximum limits (e.g., 0.05 µg/kg in infant formula).
• Pesticide residue triage: Organophosphate and carbamate detection in fruits, vegetables, and animal feed using acetylcholinesterase inhibition–based assays.
• Hygiene verification: ATP-dependent alkaline phosphatase (ALP) activity measurement as a surrogate for pasteurization efficacy and microbial load in dairy processing lines.
• Feed safety assurance: Multi-class antimicrobial residue screening in compound feeds and premixes per Codex Alimentarius GL 207–2003 guidelines.

FAQ

What regulatory frameworks recognize CHARM II 7600 assay methods?
The underlying Charm II assay formats are cited in FDA’s Milk Safety Program guidance, EU Commission Decision 2002/657/EC, Korean MFDS Notification No. 2021-49, and China’s GB/T series standards for veterinary drug residue detection.
Can the system be used for quantitative analysis?
It delivers semi-quantitative results via calibrated standard curves; for full quantification, confirmatory methods such as LC-MS/MS are recommended per ISO/IEC 17025 Clause 5.4.2.
Is method validation support available for laboratory accreditation?
Yes—Charm provides comprehensive validation kits, reference materials traceable to NIST SRMs, and technical documentation packages supporting ISO/IEC 17025 method verification and internal validation studies.
How does dual-channel operation improve assay reliability?
Simultaneous reading of test and control wells minimizes inter-assay variability caused by ambient light drift or thermal fluctuations, enhancing reproducibility across batches and operators.
Are assay kits supplied with instrument purchase?
Assay kits are sold separately and require annual reordering; each kit includes lyophilized reagents, conjugate, standards, and detailed SOPs validated for specific matrices and analytes.