Figure 1.
Illustration of the four methods of applying standards for IMS. Depositing the standards on the tissue section requires thaw-mounting the section followed by application of the standards and matrix. Deposition under the tissue section requires spotting the standards first, thaw-mounting the section on top of them, and then applying matrix. A sandwich method combines depositing the standards under and on the tissue section followed by matrix. Premixing the standard involves thaw-mounting the tissue section followed by depositing the standards and the matrix in a single solution.