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 cocrystallized with a matrix prior to analysis. 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 depending on the instrument used for analysis. To overcome the variations, a home-built robotic spinner was constructed and applied to agarose-based samples. This robotic spinner is inexpensive and easy to assemble, and when it was applied to agarose-based samples, accelerated the drying process and reduced wrinkles, improving the overall quality of the resulting IMS data.