Linear Binding Region

The linear binding region of an immunoassay standard curve is any region (usually midrange) that appears linear when the standard responses are plotted against their respective concentrations. The length of this region is only a portion of the usable concentration range of the test method and the length of this region (if present) varies among test methods. A linear binding region apparent in an immunoassay standard is not due to any fundamental relationships like the spectral properties of substances in the Beer-Lambert Law.