What is the purpose of the matrix in MALDI and which one can best be used?

The matrix layer absorbs the energy from the irradiation laser and induces desorption and ionization of the analytes. to not introduce any errors, the matrix crystal deposition should be homogenous to ensure high sensitivity, reproducibility and artefart-free imaging. for imaging proteins in the brain: 2,6-DHA matrix for imaging lipids: 1,5-DAN or CHCA.