Fig. 2
From: Molecular profiling of lung cancer specimens and liquid biopsies using MALDI-TOF mass spectrometry
Spectrograms, mass (x-axis) versus intensity (y-axis) from two histological samples (a, b) containing EGFR and PIK3CA mutations, respectively, at specific percentages of the mutated alleles (in brackets). Arrows indicate the mass peaks of the mutated alleles, using the specified decreasing amounts of DNA. The mass peaks of the wild-type alleles are also shown (WT). Using 5 ng of tumor DNA, the peak corresponding to the mutations was insufficient for a positive call for PIK3CA (b), but sufficient for EGFR