( M(Arb), M(Opt))-Scatterplot analysis of BT-474 self versus self data This plot compares the calibrated ratios obtained by LOWESS (d = 1) with the arbitrary choice of f
= 0.4 for all print-tips compared to ratios obtained with optimized f
for each print-tip group. The line of unity slope that passes through the origin shows where all the points should lay if both calibration methods produced identical ratios. For this self versus self experiment, the group of points that lay under this line shows that the arbitrary f
may improperly under-normalize these points.