An under-utilized feature of biosensors is their ability to measure active concentration. This can be particularly useful for comparing different preparations of a biological molecule, following a sample through purification, and monitoring stability under different storage conditions.

The most direct method of concentration analysis relies on comparing binding responses of unknowns to a standard. Experiments are generally set up on very high capacity surfaces, which increases the sensitivity of the assay.

The Center is working on methods for analyzing active concentration when standard samples are not available. These methods rely on measuring the binding under mass transport-limited conditions and using flow rate as a dependent variable.