Visual Inspection of Binding Data

Practicing scientists are able to make reliable estimations by visual inspecting competition curves and looking at the steepness of those curves. Such a visual inspection is based on the following line of reasoning between the apparent steepness of a competition curve and the derived Hill coefficient. First, consider that the indirect Hill equation can take the following form  

From this equation, we can construct an example that is extremely useful in visually examining receptor data, indeed any data fitting the simple mass action model of Eq. (19.1). This means that a toxicant under study is competing with the radioligand for one, and only one, population of sites. By definition, the Hill slope (often called nH) must equal 1. It turns out that by memorizing the numbers 9 and 91, one can do a very useful preliminary analysis of data fit to such a mass-action model. The reason for this is as follows  

100-fold) concentration range. This is a very useful way to estimate whether data are consistent with the bimolecular model. 

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