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Paste in X, Y values:

Paste in the X and Y values here. Each X value must be a ligand concentration and it should be followed by the corresponding experimental measurement, Y, with an intervening space or text separator. Usually there would be one X and Y value per line (e.g. if pasting from a spreadsheet) although the X and Y pairs can be entered in one line, if so desired. Duplicate measurements can be entered all together in the same manner as the corresponding pairs of X and Y values e.g. one X, Y pair per line. Data can be entered as ordinary decimal numbers, integers, exponentials ('E' or 'e' notation) or a mixture of these formats. Non-numerical text should not matter since the program will try to remove it. If the plot does not appear or the curve does not fit well please check that the data are entered correctly. Sometimes to get the fitting routine to work better you need to rescale the X-values by several orders of magnitude, e.g. by converting them all from M to mM, uM or nM, etc, or vice versa. It definitely is worth spending time rescaling all the values on an axis if the fitting routine does not work well initially. To force the line of best fit to intersect the origin, click the check-box below and then click on the Submit button again. Note that the fitting relies on the measurements at the lowest and highest values of X providing reasonable estimates of the Y-asymptotes. The mean value of Y is used to estimate the middle Y-asymptote and the fitting relies on the range of X-values sampling the biphasic curve in a reasonably symmetrical manner.

Tick here and re-submit to make curve start at origin.