Binding assays measure how strongly a compound associates with its molecular target, reporting the result as an affinity value that lets researchers compare compounds. This guide explains the concept and formats.
What affinity means
Affinity describes how tightly a compound and its target bind. Higher affinity means the two associate more strongly and stay bound longer under the assay's conditions.
Competition binding assays
A common format measures how a test compound competes with a labeled reference molecule for the same target. The amount of competition reflects the test compound's affinity.
Direct binding assays
Other formats measure binding directly, for example by detecting a signal that changes when a compound associates with its target.
Why affinity is measured
Affinity is a defining property of a compound-target pair, so measuring it is central to characterizing reference compounds in a controlled system.
Related research guides
- In-vitro methods & assays (overview)
- Cell viability & proliferation assays
- Controls & replicates
- Verify peptide purity
Research-use note
All compounds referenced are supplied for in vitro laboratory research use only. They are not for human or animal use.
Related research: Reconstitution Solution.
