Fig. 2

Determination of optimal ALK primary antibody incubation time. a Tissue cuts (Case N°12) were incubated for 2, 4, 8, 16, or 32 min either with PBST 0.05% (CTL NEG, first row) or the anti-human ALK antibody (ALK, second row). The incubation time of the secondary antibody was kept constant at 8 min. The same region of interest (ROI) is presented for ALK IF and its negative control. Scale bar is 10 μm. b Quantification of the ALK stained slides shown in (a). For each incubation time, 25 ROIs were manually placed in areas of ALK+ tumor epithelia and in areas of stroma only. The graph shows the average of the mean intensities of all 25 ROIs for ALK+ tumor epithelia (blue) and stroma (orange) with corresponding standard deviations