Figure 1

A typical set of ELISA data, standard curve (filled squares) and sample (open squares), are presented with the best fits of the data. The duplicate standards and sample data are globally fitted to an exponential function Aexp(c _i + β _i /τ), where c _i is the concentration of (PC-tubulin-derived) β-tubulin isotype in each dilution and β _i is the concentration of breast tissue β-tubulin isotype in each sample, corrected for dilution. The sample data are then corrected for this additional concentration of breast tissue isotype and plotted with the standard curve and the best fit to demonstrate the goodness of fit. Fits of these data resulted in the following concentrations for β-tubulin classes: I + IV, 4.09 μg/ml; III, 2.27 μg/ml; II, 18.34 μg/ml. Triplicate ELISA data for each tissue sample were fitted separately and then averaged to give the final results and standard deviations (Fig. 5).