Overview
ISO/TS 20224-8:2022 specifies a real-time PCR method for the qualitative detection of turkey DNA (Meleagris spp.) in foodstuffs and feedstuffs. Designed for molecular biomarker analysis and species identification, the technical specification targets a partial fragment of the Meleagris gallopavo chromosome Z sequence (GenBank NC_015041.2). The assay is applicable to both domestic turkey (M. gallopavo) and wild/ocellated turkey (M. ocellata) material and requires extraction of PCR-amplifiable DNA from the tested matrix.
Keywords: ISO/TS 20224-8:2022, turkey DNA detection, real-time PCR, molecular biomarker analysis, species identification, food and feed testing, LOD95%.
Key topics and requirements
- Target and analytical sensitivity
- Target: single-copy fragment of Meleagris gallopavo chromosome Z (NC_015041.2).
- Performance: absolute limit of detection 5 copies per reaction with ≥95% confidence (LOD95%).
- Assay chemistry and oligonucleotides
- TaqMan format probe-based real-time PCR. Provided oligonucleotides (from the document):
- Turkey-118bp-F: 5′-TGAACAAATCCACTTCCCTTTAACC-3′ (400 nmol/L)
- Turkey-118bp-R: 5′-TCATTTCTGCTGCACAAAGTGAG-3′ (400 nmol/L)
- Turkey-118bp-P: 5′-[FAM]-TGATGACGAGCCGCAGCCACACC-[TAMRA]-3′ (200 nmol/L)
- Reaction setup (typical)
- Total volume: 25 µL (5 µL sample DNA, 12.5 µL 2× PCR master mix, primers/probe and water).
- Sample DNA input recommended: 20–200 ng/µL (5 µL added).
- Requires a real-time thermocycler capable of fluorescence excitation/detection.
- Controls and quality checks
- Verification of DNA quality/amplifiability using reference assays (e.g., 18S rRNA for eukaryotes or myostatin for mammals/poultry).
- Standard PCR controls and inhibition checks per ISO 24276 and ISO 20813.
- Procedural elements
- Sample homogenization, DNA extraction/purification per ISO 21571, and interpretation/acceptance criteria as defined in the specification.
- Validation and performance
- Document addresses robustness, reproducibility, sensitivity and specificity testing and provides bioinformatics (BLAST) confirmation and digital PCR quantification support.
Applications and users
- Practical applications
- Detection of turkey adulteration or contamination in processed foods and animal feeds.
- Regulatory compliance testing, food authentication, halal/kosher assurance, and forensic food analysis.
- Who uses this standard
- Food and feed testing laboratories, regulatory agencies, contract testing services, quality assurance teams in food production, and researchers working on species authentication and food fraud detection.
Related standards
- ISO 21571 - DNA extraction for foodstuffs
- ISO 20813 - General nucleic acid-based methods for animal species detection
- ISO 24276 - PCR general requirements and definitions
- ISO 16577 - Vocabulary for molecular biomarker methods
This ISO/TS provides an actionable, validated real-time PCR workflow for reliable turkey DNA detection in food and feed matrices, supporting accurate species identification and food authenticity testing.