Fig. 4.

Positive ion MALDI IMS of VLC-PUFA-containing PC lipids in human ocular tissue. A: H&E stain of ocular tissue section immediately adjacent to the section used for MALDI imaging. B: Inset enlarged from (A) showing a region where the photoreceptor layer is detached from the inner retina (arrow). C: Total positive ion MALDI mass spectra of the retina directly from the ocular section. The solid black diamonds indicate background ions from the embedding agent. Extracted positive ion MALDI images of the [M+Na]⁺ of PC(40:6) (m/z 856.6) (D), PC(44:12) (m/z 900.6) (E), and PC(56:11) (m/z 1,070.7) (F). G: Merged positive ion MALDI image of PC(56:11) (green), PC(44:12) (red), and PC(40:6) (blue). Arrows denote the layer of photoreceptors that have been detached from the inner retina. GCL, ganglion cell layer;