IJCA - Volume 3 - Flipbook - Page 57
2024 | Volume 3, Issue 1
55
Application of ISO 16140-3:2021 – Key
Concepts and Examples of Veri昀椀cation of
Alternative Methods
By DeAnn L. Benesh, Global Scienti昀椀c Affairs Manager, Neogen | DOI: 10.55459/IJCA/v3i1/DB
-ABSTRACTVeri昀椀cation of the methods routinely used in
the laboratory is a requirement for laboratories
accredited to the International Organization for
Standardization (ISO) standard: ISO/IEC 17025:2017
General requirements for the competence of testing
and calibration laboratories.1 A method veri昀椀cation
protocol is not speci昀椀ed within the ISO 17025:2017
standard, and until now, laboratories have been
required to conduct their veri昀椀cation studies based on
protocols either developed in-house, or using locally
recognized protocols, such as: NATA Technical Note
17,2 Health Canada Compendium of Methods,3 etc.
The publication of ISO 16140-3:2021 Microbiology of
the food chain — Method validation — Part 3: Protocol
for the veri昀椀cation of reference methods and validated
alternative methods in a single laboratory4 now
provides an internationally developed and recognized
protocol that may be used to ful昀椀ll this requirement.
An orientation to some of the key concepts within
the ISO 16140-3:2021 standard is presented and
demonstrated using examples of veri昀椀cation of both
a qualitative method (Neogen® Molecular Detection
Assay 2 – Salmonella (MDA2 SAL) and a quantitative
method Neogen® Petri昀椀lm® Enterobacteriaceae Count
Plate (Petri昀椀lm EB Plate).
Keywords: ISO 17025, ISO 16140-3, ISO TC34/TC9, AOAC O昀케cial
Methods of Analysis, MicroVal Certi昀椀cation,
AFNOR Certi昀椀cation, method veri昀椀cation
Introduction
Food microbiology laboratories are tasked with
testing a diverse range of foods and beverages. They
must ensure that the methods they employ for testing
are both validated and verified, particularly for the
specific sample types that they routinely analyze.
The ISO standard, 16140-3:2021, was developed
to demonstrate user competency to perform and
implement validated laboratory methods. This
standard, published in 2021, is designed for verifying
both qualitative and quantitative methods, along
with confirmation and typing methods. This article
provides an overview of key concepts covered in the
standard and subsequently guides readers through
the verification process using specific examples for
qualitative and quantitative methods. It is the hope
that this overview and the examples provided will instill
confidence in readers, equipping them to navigate
the standard’s intricacies and apply it effectively for
verifying validated methods in their laboratories.
General Concepts Within the Standard
Fully validated methods
The ISO 16140-3 standard on method verification
can be applied to methods that have been “fully”
validated. “Full” validation refers to a method
validation compared to a reference method that
included both a comparative study and an interlaboratory study, as described below:
• Comparative study—a method comparison to a
reference method, usually conducted within one
laboratory.
• Inter-laboratory study (ILS)—a method
comparison to a reference method, conducted
between many laboratories.
Validation vs. verification
The terms validation and verification are often
(incorrectly) used interchangeably, so it is important
to understand their distinction and definitions.
Method verification always follows validation. A
method is first validated, demonstrating that the
method performs equivalently to the reference
method, based on key, defined method criteria. Then,
before a laboratory puts the validated method into
routine use, it needs to verify that its personnel can
correctly use the validated method and achieve those
key method criteria. In simple terms:
• Validation is proof that the method “works.”
• Verification is proof that the user can perform the
method correctly.
