ISO 8981-1993 PDF

Full title and description

ISO 8981:1993 — Wheat — Identification of varieties by electrophoresis. Specifies a laboratory method for identifying wheat varieties (soft or hard wheat) in kernels, flour, farina or semolina by separating gliadin proteins using polyacrylamide slab‑gel electrophoresis with an aluminium‑lactate buffer system.

Abstract

This standard defines a protocol for extracting gliadin (prolamin) proteins from wheat samples and resolving them by polyacrylamide gel electrophoresis (PAGE) in slab gels containing an aluminium‑lactate buffer (acidic system). The resulting electrophoretic “fingerprint” is used to compare unknown samples against reference patterns for variety identification and purity assessment; the document includes reagents, gel preparation, electrophoresis and documentation guidance.

General information

• Status: Withdrawn (withdrawal proposed and later confirmed; see lifecycle notes).
• Publication date: November 1993 (First edition, 1993).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 67.060 — Cereals, pulses and derived products.
• Edition / version: Edition 1 (1993).
• Number of pages: 8 pages.

Scope

Applies to laboratory identification of wheat varieties by separation of gliadin fractions using PAGE in slab gels buffered with aluminium lactate (acidic PAGE). It covers sample types (individual ground kernels, flour, farina, semolina), extraction and reagent requirements, gel casting and electrophoresis conditions, visual or photographic documentation of banding patterns, and comparison against reference patterns for variety identification. The method is intended for use in seed testing, variety registration and research where biochemical fingerprinting is appropriate.

Key topics and requirements

• Extraction of gliadin/prolamin proteins from wheat material (kernels, flour, semolina) using specified solvents and procedures.
• Preparation and casting of polyacrylamide slab gels formulated for an aluminium‑lactate buffer at acidic pH to resolve gliadin bands.
• Electrophoresis operating parameters (voltage/current/time) and controlled temperature for reproducible banding.
• Staining, visualization and photographic documentation of gel patterns; creation and use of reference pattern sets for variety matching.
• Interpretation rules and acceptance criteria for identification and purity assessment of wheat lots.
• Laboratory safety considerations for acrylamide and other reagents used in PAGE procedures.

Typical use and users

Primary users are seed testing laboratories, plant breeders, variety registration and certification authorities, genebanks and research institutions needing a biochemical fingerprinting method for wheat variety identification, varietal purity checks, and genetic/heritage studies. The method is commonly used where protein electrophoretic profiles (gliadin patterns) provide stable variety markers that complement morphological and molecular methods.

Related standards

Standards and documents from the same technical area (ISO/TC 34/SC 4 — cereals and pulses) include other ISO methods for wheat and wheat‑flour analysis (for example, ISO 21415 series on gluten determination) and national/adopted equivalents that relate to cereal testing. Some national or regional equivalents/identical texts have been published alongside ISO 8981:1993 in the past.

Keywords

wheat; gliadin; electrophoresis; PAGE; aluminium‑lactate buffer; variety identification; seed testing; protein fingerprinting; ISO 8981:1993; cereals.

FAQ

Q: What is this standard?

A: ISO 8981:1993 is an ISO laboratory standard that specified a method for identifying wheat varieties by electrophoretic separation of gliadin proteins.

Q: What does it cover?

A: It covers sample preparation (ground kernels, flour, farina or semolina), gliadin extraction, polyacrylamide slab‑gel electrophoresis in an aluminium‑lactate (acidic) buffer system, staining/photography of banding patterns and comparison procedures for variety identification. It does not cover unrelated cereal‑testing properties (e.g., baking quality measurements) beyond its electrophoretic identification purpose.

Q: Who typically uses it?

A: Seed testing and certification laboratories, plant breeders, genebanks, research groups working on wheat varietal identification, and agencies involved in varietal registration and purity assessment.

Q: Is it current or superseded?

A: ISO 8981:1993 has been withdrawn. The ISO record lists the standard as withdrawn (life‑cycle: withdrawal proposed and confirmed), and commercial catalogues note a withdrawal entry (withdrawn in 2021 in distributor records). Users should check current ISO/TC 34/SC 4 publications for replacement or alternative methods before relying on this 1993 procedure.

Q: Is it part of a series?

A: It is a standalone ISO method prepared under ISO/TC 34/SC 4 (cereals and pulses). Related ISO standards address other wheat and flour analyses (e.g., gluten determination) and national/adopted equivalents exist for some countries.

Q: What are the key keywords?

A: Wheat, gliadin, electrophoresis, PAGE, aluminium‑lactate buffer, variety identification, seed testing, protein fingerprinting, ISO 8981:1993.