Cryo-ultramicrotomy and Mass Spectrometry Imaging Analysis of Nudibranch Microstructures.

In this paper, we investigate the presence of latrunculin A in the outer rim of a nudibranch Chromodoris kuiteri and show that by combining ultrathin cryosection methods with MALDI MSI we can achieve improved lateral ( x and y ) resolution and very high resolution in the z dimension by virtue of the ultrathin 200 nm thin cryosections. We also demonstrate that a post ionization laser increases sensitivity. Recent advances in MALDI source design have improved the lateral resolution ( x and y ) and sensitivity during MSI. Taken together, very high z resolution, from ultrathin sections, and improved lateral ( x and y ) resolution will allow for subcellular molecular imaging with the potential for subcellular 3D volume reconstruction.