Home-built spinning apparatus for drying agarose-based imaging mass spectrometry samples

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a useful technique for mapping the spatial distribution of molecules across biological samples. Sample preparation is crucial for MALDI-IMS; samples must be flat, dry, and co-crystallized with a matrix prior to analysis. Agar and agarose-based samples can be difficult to consistently prepare as they are susceptible to environmental changes, which can lead to inconsistent drying and wrinkling on the sample surface. Small height differences may cause low ionization of target analytes, or introduce artifacts in imaging data. To overcome the variations, a home-built robotic spinner was constructed and applied to agarose-based samples. This robotic-spinner is inexpensive, easy to assemble; and when applied to agarose-based samples, accelerated the drying process and reduced wrinkles, improving the overall quality of the resulting IMS data.