Scientific Glossary

Counterion

An ion associated with a species of opposite charge.

2026-09-09

Editorial educational content. Specialist review is not claimed; consult the original references and limitations.

Definition and context

An ion associated with a species of opposite charge.

What to check

Confirm whether the material is described as acetate or trifluoroacetate; distinguish salt form from covalent sequence modifications.

Interpretation

Changing the counterion does not establish analytical equivalence.

Sources and verification scope

Scientific publication · S04

Therapeutic peptides: current applications and future directions ↗

Wang et al. · Signal Transduction and Targeted Therapy

Source details (original language)
Scope
Review of therapeutic peptide development
Document section
Introduction; production, modification and applications
Limitations
Historical review, not validation of products or batches. More than 80 approved drugs is a 2022 literature statement.
Claim verification date
2026-09-09

Related reading

Scientific Glossary · Manufacturing & Quality

Acetate

A species derived from acetic acid that can serve as a counterion.

Read details →
Scientific Glossary · Manufacturing & Quality

TFA

An abbreviation for trifluoroacetic acid; trifluoroacetate may be present as a counterion.

Read details →