ISO 21572:2019

Overview

ISO 21572:2019 - Foodstuffs: Molecular biomarker analysis - Immunochemical methods for the detection and quantification of proteins - specifies performance criteria and analytical considerations for immunochemical methods used to detect and/or quantify specific protein(s) of interest (POIs) in food and related matrices. The standard covers general principles, sample preparation, extraction, assay procedures (including ELISA and lateral flow devices in Annexes A and B), interpretation of results and relevant performance parameters for protein detection and quantification.

Key topics and technical requirements

• Scope and principle
  • Focuses on immunochemical assays that use antibody–antigen binding to detect or quantify target proteins extracted from a representative sample.
• Sample preparation & extraction
  • Guidance on preparing representative test portions, grinding, extraction buffers and matrix-appropriate procedures. Emphasises validated extraction methods and proper storage of extracts.
• Reagents and equipment
  • Use of analytical-grade reagents and low protein-binding laboratory consumables; storage and shelf-life of kits (LFDs, antibodies, conjugates) must be specified.
• Assay setup & calibration
  • Procedures for preparing calibration curves, positive/negative controls and matrix-matched reference materials for quantitative assays (ELISA). Qualitative tests (LFDs) may use controls at analyst discretion.
• Performance parameters to evaluate
  • Selectivity, extraction efficiency, matrix effects, assay applicability, hook effect, parallelism/linearity, limits of detection (LOD) and limits of quantification (LOQ).
• Quality assurance and reporting
  • Recommendations on laboratory QA (referencing ISO/IEC 17025), double determinations, blanks, calibration, confirmatory testing and required elements of the test report.
• Annexes
  • Practical example procedures for ELISA (Annex A) and lateral flow devices (Annex B).

Practical applications

ISO 21572:2019 is directly applicable to:

• Allergen testing and labelling verification
• Detection of newly expressed proteins in biotech crops (GMO monitoring)
• Food safety screening and quality control during food processing and marketing
• Biotechnology product testing and disease indexing where specific protein biomarkers are analysed
• Development and validation of immunoassay-based kits (ELISA and LFD manufacturers)

Who should use this standard

• Food testing laboratories and quality assurance teams
• Regulatory and inspection authorities
• Diagnostic and kit manufacturers (ELISA, LFD)
• Researchers in food safety, molecular biomarker analysis and biotechnology
• Producers and processors implementing protein-based testing for compliance or product claims

Related standards

• ISO 16577 - Molecular biomarker analysis - Terms and definitions
• ISO/IEC 17025 - General requirements for the competence of testing and calibration laboratories

Keywords: ISO 21572:2019, immunochemical methods, protein detection, ELISA, lateral flow devices, molecular biomarker analysis, food safety, allergen testing, matrix effects, limits of detection.