Quantitative analysis of samples using a Cubic Spline. All samples are first corrected by the mean of the blank group measurements. The standard data points are plotted (concentration vs. corrected measurement) and a Cubic Spline is applied to these points. The concentrations of the unknown samples are determined from the fit. For measurements outside the range of the standards a linear extrapolation is used.

Quantitative determination of TSHR autoantibodies in human serum using a Cubic Spline for calculation of TRAb concentrations. Raw absorbance measurements at 450nm are first corrected by the mean of the blank group measurements. The standard data points are plotted (concentration vs. corrected) and a Cubic Spline is applied to these points. The concentrations of the unknown samples are determined from the fit. Samples outside the range of the standards are marked as < 0.4 or > 30 accordingly.