M/Z: 448.0207

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.

Supplementary Figure S6. Ion distribution images for (a) [PC36:4+Na]+ (m/z 804.5514) and (b) [PC38:6+Na]+ (m/z 828.5515) obtained from mouse lung tissue collected 6 h after administration of D9- choline and U13C-DPPC–containing CHF5633. Parts-per-million (ppm) mass errors are indicated in parentheses. (c) Magnification of the boxed region in (a) with selected bronchiolar regions outlined in white boxes. (d) The corresponding H&E-stained tissue section with the same selected bronchiolar regions outlined in black boxes. These data demonstrate the co-localisation of the polyunsaturated lipids PC36:4 and PC38:6 with the bronchiolar regions of the lung. All MSI images were visualised using total ion current normalisation and hotspot removal (high quantile = 99%).

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).