Testing & Verification
Potency Assay
Overview
A potency assay characterises activity — a different question from purity (what proportion is the main component) and quantity (how much is present). Identity ≠ Purity ≠ Assay ≠ Quantity.
What potency means
Potency refers to activity — a measure of how much effect or functional capacity a material has, in an analytical sense defined by the assay used. It is conceptually distinct from purity and quantity: a material could be present in a known amount and known proportion yet still be characterised separately for its activity.
Why assay is separate from purity and quantity
Purity is a proportion (of detected material, how much is the main component). Quantity is an absolute amount (how much is present). Potency/assay concerns activity. Because these answer different questions, they are measured and reported separately — no single one implies the others. This is the core “Identity ≠ Purity ≠ Assay ≠ Quantity” distinction.
What an assay result describes
A potency-assay result characterises activity within the scope of the method used. It does not by itself establish identity, the purity percentage, or the absolute quantity, and it is not a statement about suitability for any use.
What this test can and cannot establish
What it can establish
- A characterisation of activity within the method’s scope
- A measurement distinct from purity and quantity
What it cannot establish
- Identity, the purity proportion, or the absolute quantity on their own
- Any suitability, safety, or appropriateness for any use
Key terminology
- Potency / assay
- A measurement of activity, distinct from purity and quantity.
- Purity
- The proportion of detected material that is the main component.
- Quantity
- The absolute amount of the intended substance present.