Glutaraldehyde and Uranyl Acetate Dual Fixation Combined Sputtering/Unroofing Enables Intracellular Fatty Acids TOF-SIMS Imaging with Organelle-Corresponding Subcellular Distribution.

Fatty acids (FAs) have diverse functions in cellular activities. The intracellular distribution of FAs is critical for their functions. Imaging of FAs by TOF-SIMS has been achieved. However, TOF-SIMS images of FAs so far do not have subcellular distribution due to inadequate sample preparation methods. In this study, we developed a chemical fixation method using glutaraldehyde (GA) with uranyl acetate (UA), which preserved cellular structure and intracellular FA distribution well. Combining GA+UA fixation with sputtering-based methods and unroofing-based methods, respectively, we successfully imaged intracellular lipids with the subcellular distribution.