Fig. 2: MALDI-MS imaging of ¹³C-labeled glycogen in mouse liver tissue.

A Schematic of sample processing and MALDI mass spectrometry (MS) imaging of mouse livers from control and ¹³C-labeled mice. B Cartoon illustration of a mature glycogen molecule (top) where alpha-1-6-glycosidic linkages are shown. These linkages are targeted by isoamylase digestion to release glucose polymers (GP) of different sizes (below). Grey and teal dots represent ¹²C and ¹³C-labeled glucose molecules, respectively. C Representative images of hematoxylin and eosin (H&E) staining (top), and total glycogen content map measured using MALDI-MS of a mouse liver section after 4 hours of [U-¹³C₆]-glucose infusion. Scale bar, 1 mm. D Same as in C, however MALDI-MS images show the spatial pattern of a specific ¹²C- and ¹³C-labeled glucose polymer (GP) with six glucose molecules (GP6). In each panel, the number after “¹³Cx” indicates the number of ¹³C-labeled molecules found in GP6. In A–D), data representative of n = 3 mice. A, B created using biorender.com.