ISO 22119:2011

Overview

ISO 22119:2011 - "Microbiology of food and animal feeding stuffs - Real-time polymerase chain reaction (PCR) for the detection of food‑borne pathogens - General requirements and definitions" sets out the definitions and minimum requirements for real‑time PCR (qPCR) methods used to detect food‑borne pathogens in foodstuffs, isolates, environmental samples and animal feeding stuffs. The standard defines terms and specifies requirements for the amplification and detection of nucleic acid sequences (DNA or RNA after reverse transcription) by real‑time PCR to ensure comparable and reproducible results within and between laboratories.

Key topics and technical requirements

• Terms and definitions for real‑time PCR, PCR product, probes, reporters, quenchers, baseline/background fluorescence, threshold cycle, etc.
• Principle of real‑time PCR: amplification in the presence of fluorescent probes, cycle‑by‑cycle fluorescence generation, optical detection and data analysis.
• Probe types and detection chemistries described:
  • Hydrolysis probes (e.g., TaqMan) - reporter/quencher separated by 5′–3′ exonuclease activity.
  • Hybridization probes - donor/acceptor pairs using FRET.
  • Molecular beacons - stem‑loop probes that fluoresce on target hybridization.
• General laboratory requirements aligned with ISO 22174 to minimize contamination and ensure quality.
• Reagents and materials expectations: high‑purity water, analytical grade reagents, thermostable DNA polymerase (with reverse transcriptase activity where needed), reaction buffers, dNTPs, primers and probes.
• Procedure components: sample preparation, amplification conditions, inclusion of controls (positive, negative, internal amplification controls), fluorescence data acquisition and analysis.
• Documentation and evaluation: record keeping, result interpretation and reporting to support reproducibility and comparability.

Applications and users

ISO 22119 is intended for organizations and professionals involved in microbial testing and method development for food safety:

• Food testing laboratories and quality assurance teams
• Public health and clinical laboratories performing food‑borne pathogen surveillance
• Veterinary diagnostic and animal feed testing laboratories
• Method developers, kit manufacturers and instrument vendors
• Accreditation bodies and regulators seeking standardized, validated qPCR practice

Practical applications include routine screening for Salmonella, Listeria, STEC and other food‑borne pathogens, environmental monitoring in food production, and validation of diagnostic assays.

Related standards

ISO 22119 is part of a PCR standards series. Relevant documents include:

• ISO 22174 (general PCR requirements and definitions)
• ISO 20838 (amplification/detection for qualitative methods)
• ISO 22118 (performance characteristics for detection and quantification)
• ISO 20837, ISO/TS 20836 and other ISO/CEN publications on PCR performance and sample preparation

Keywords: ISO 22119, real‑time PCR, qPCR, food‑borne pathogens, microbiology of food, nucleic acid amplification, hydrolysis probe, molecular beacon, laboratory requirements.