ISO 16921-1:2026

International
Standard
ISO 16921-1
First edition
Biotechnology — Gene delivery
2026-01
systems —
Part 1:
Vocabulary
Biotechnologie — Systèmes de transfert de gènes —
Partie 1: Vocabulaire
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms .1
3.2 Gene delivery system attributes and function .5
3.3 General terms for viral vectors .6
3.4 General terms for lipid nanoparticles .8
3.5 Analytical methods .8
Bibliography .12

iii
Foreword
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Analytical methods.
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iv
Introduction
Modern and emerging biotechnology is underpinned by the ability to manipulate the genes and genomes of
living systems. Gene delivery systems are foundational to genome engineering. Gene delivery technology is
evolving rapidly with numerous types of gene delivery systems providing a comprehensive set of tools and
capabilities for in vitro or in vivo targeted delivery.
The ISO I6921 series consists of multiple parts to provide common understanding, guides, and analytical
methods for characterizing these emerging biotechnology tools. This document provides terms and
definitions to enable common understanding. Other parts of the ISO I6921 series will focus on measurements
for various gene delivery systems.

v
International Standard ISO 16921-1:2026(en)
Biotechnology — Gene delivery systems —
Part 1:
Vocabulary
1 Scope
This document defines terms related to gene transfer for mammalian systems, including the use of viral and
non-viral gene delivery systems and via mechanical mechanisms.
This document is applicable to the development, measurement, and use of gene delivery systems for all
applications.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General terms
3.1.1
electroporation
action or process of introducing nucleic acids into cells using a pulse of electricity to briefly open pores in
the cell membrane
3.1.2
exosome
subtype of extracellular vesicles (3.1.3) of endosomal origin generated by cells that can carry nucleic acids,
proteins, lipids, and metabolites
Note 1 to entry: Usage of this term is discouraged unless subcellular origin can be demonstrated. See Reference [1] for
additional information.
3.1.3
extracellular vesicles
particles that are released from cells, are delimited by a lipid bilayer (3.4.3), and cannot replicate on their
own
Note 1 to entry: See Reference [1] for additional information.
[1]
[SOURCE: Minimal information for studies of extracellular vesicles (MISEV2023) ]
3.1.4
gene amplification
process whereby a defined DNA sequence in the genome is increased exponentially in number of copies
using methods such as PCR or bacterial amplification

3.1.5
gene cloning
technique of identifying a gene of interest (3.1.10), isolating the gene, and amplifying a gene that can be
incorporated into a gene delivery system (3.1.6)
3.1.6
gene delivery systems
systems to introduce foreign nucleic acid into target or host cells
Note 1 to entry: Foreign nucleic acid to be delivered are commonly known as transgenes (3.1.27).
3.1.7
gene editing
techniques for genome engineering (3.1.13) that involve nucleic acid damage, repair mechanisms, replication
and/or recombination for incorporating site-specific modification(s) into genomic DNA
Note 1 to entry: Gene editing is a subclass of genome editing (3.1.12).
[SOURCE: ISO 5058-1:2021, 3.1.1, modified — changed “into a gene or genes” to “into genomic DNA” and
removed Note 2 to entry.]
3.1.8
gene expression
process of gene transcription and translation, in which the product is RNA or protein
[SOURCE: ISO/TS 16843-6:2022, 3,27, modified — Example removed.]
3.1.9
gene gun
mechanical gene transfer (3.1.11) method for transfecting cells with foreign nucleic acid or other biological
molecules where a payload is coated on to high-density microcarriers, accelerated to high velocity by a gas
pulse, and driven through cell walls and membranes to enter a target cell
3.1.10
gene of interest
GOI
nucleic acid sequence that encodes for the protein of interest
3.1.11
gene transfer
gene delivery
process by which foreign nucleic acid is introduced to target or host cells through mechanical, chemical, or
biological approaches
Note 1 to entry: There are various gene transfer methods (see Figure 1).

a
Viral vectors can include, but are not limited to, lentivirus, adenovirus, adeno-associated virus, and retrovirus.
NOTE This figure of gene transfer methods is not exhaustive as methods are under development.
Figure 1 — General classification for gene transfer
3.1.12
genome editing
techniques for genome engineering (3.1.13) that involve nucleic acid damage, repair mechanisms, replication
and/or recombination for incorporating site-specific modification(s) into a genomic DNA
Note 1 to entry: Gene editing (3.1.7) is a subclass of genome editing.
[SOURCE: ISO 5058-1:2021, 3.12, modified — deleted Note 2 to entry and the associated Figure 1.]
3.1.13
genome engineering
process of introducing intentional changes to genomic nucleic acid
[SOURCE: ISO 5058-1:2021, 3.1.3, modified — deleted Note 1 to entry.]
3.1.14
integrating gene transfer
nucleic acid payload integration into the target host genome
Note 1 to entry: Integrating gene transfer (3.1.11) methods include retrovirus transduction and CRISPR/Cas9-
mediated gene editing.
3.1.15
lipofection
delivery of nucleic acids to target cells by lipid transfer

3.1.16
mechanical gene transfer
transfer of nucleic acid to target cells by physical mechanisms
Note 1 to entry: Microinjection, electroporation, gene gun, ultrasound-mediated methods and hydrodynamic systems
are examples of mechanical methods used for gene delivery (3.1.11).
3.1.17
microbial vector
microbial system engineered for delivering payload to cells
3.1.18
microinjection
method for injecting nucleic acid directly into a specific, individual cell using a micropipette
3.3.19
non-integrating gene transfer
transient gene transfer
nucleic acid payload transfer that does not integrate into the target host genome, but allows the gene to be
expressed for a limited period of time
3.1.20
nucleic acid nanostructure
gene delivery (3.1.11) method based on encapsulation of payload using nucleic acids to form complexes or
structures that can deliver genetic material into cells
Note 1 to entry: Examples of nucleic acid nanostructures include tetrahedral framework nucleic acid (3.1.24), DNA
nanostructures, and RNA nanoparticles.
Note 2 to entry: Nucleic acid nanostructures can conjugate with other materials, such as polymers, resulting in a
hybrid gene delivery system (3.1.6).
3.1.21
plasmid
extrachromosomal DNA molecule in cells physically separated from the chromosome and capable of
autonomous replication
[SOURCE: ISO 16577:2022, 3.4.37, modified — deleted Notes 1 and 2 to entry.]
3.1.22
polymeric nanoparticles
gene delivery (3.1.11) method based on encapsulation of payload using polymers
Note 1 to entry: Examples of synthetic polymer gene delivery systems (3.1.6) include poly-L-lysine, polyethyleneimine
or hydrogels.
Note 2 to entry: Examples of natural polymer gene delivery systems (3.1.6) include polysaccharides, such chitosan,
dextran, and hyaluronic acid.
3.1.23
protein nanocarriers
gene delivery (3.1.11) method based on encapsulation of payload using proteins
Note 1 to entry: Examples of protein nanocarriers include albumin nanoparticles and virus-like particles.
3.1.24
tetrahedral framework nucleic acid
tFNA
nucleic acid nanostructure (3.1.20) with a tetrahedral framework structure developed through DNA origami
technology, formed from four single-stranded DNA molecules through denaturation and renaturation,
relying on inter-strand complementary base pairing

3.1.25
transduction
process whereby genetic material is introduced into a host cell by a replication incompetent (3.3.12) viral
vector (3.1.28)
3.1.26
transfection
introduction of nucleic acids, exogenous DNA, or RNA into a eukaryotic cell by non-viral methods
3.1.27
transgene
gene from one organism or synthetically generated that can include promoter, gene of interest (3.1.10), and
stop sequence that is inserted into another cell or organism
Note 1 to entry: The terms payload and cargo are sometimes used to describe a transgene.
3.1.28
viral vector
recombinant viral system engineered to be replication incompetent (3.3.12) for delivering payload to cells
3.2 Gene delivery system attributes and function
3.2.1
activity
measure of a specific cellular functional outcome associated with gene transfer (3.1.11) which can include
transgene (3.1.27) insertion, integration, and expression
Note 1 to entry: Potency assays are a type of activity assay that are often associated with a product’s specific
mechanisms of action.
3.2.2
aggregate
two or more particles clustered together (tightly or loosely) and detected as a larger object
[SOURCE: ISO 20391-1:2018, 3.3, modified — used "particles" instead of "cells" and deleted Note 1 to entry.]
3.2.3
cellular uptake
absorption of biological or manufactured entity into a cell through its plasma membrane
3.2.4
concentration
number of individual particles per unit volume
[SOURCE: ISO 14644-3:2019, 3.2.4, modified — removed “of air” and added
...