In competitive binding assays, the logit-log dose relationship, in which the response is defined by:

R = logit (y) = lg (y/(1 – y))

where y = b/b₀ with b = fraction of tracer bound and b₀ = value of b with no unlabelled ligand in the system.

Note: Logit-transformed assay data frequently yield straight-line dose-response data, amenable to statistical analysis. More generally in toxicology, the transformation is applied to dose-response data where b0 denotes the maximum response in the absence of a toxic substance.