M/Z: 703.5572

Mass spectrometry imaging of phospholipids in mouse urinary bladder (imzML dataset)
The spatial distribution of phospholipids in a tissue section of mouse urinary bladder was analyzed by MALDI MS imaging at 10 micrometer pixel size with high mass resolution (using an LTQ Orbitrap mass spectrometer).

R, ö, mpp A, Guenther S, Schober Y, Schulz O, Takats Z, Kummer W, Spengler B, Histology by mass spectrometry: label-free tissue characterization obtained from high-accuracy bioanalytical imaging. Angew Chem Int Ed Engl, 49(22):3834-8(2010)

Fig. S2: Single ion images of compounds shown in Fig. 1A-B : (upper left to lower right) m/z = 743.5482 (unknown), m/z = 741.5307 (SM (16:0), [M+K]+), m/z = 798.5410 (PC (34:1), [M+K]+), m/z = 616.1767 (heme b, M+), m/z = 772.5253 (PC (32:0), [M+K]+).

Stability of determined mass values was in the range of +/- 1 ppm over 22 hours of measurement (Fig. S4), with a standard deviation of 0.56 ppm. Accuracy data were obtained during tissue scanning experiments by monitoring the mass signal at nominal mass 798. The internal lock mass function of the Orbitrap instrument was used for automatic calibration during imaging measurements, using the known matrix-related ion signals at m/z = 137.0233, m/z = 444.0925 and m/z = 716.1246.

The human colorectal adenocarcinoma sample was excised during a surgical operation performed at the Imperial College Healthcare NHS Trust. The sample and procedures were carried out in accordance with ethical approval (14/EE/0024).