Methods of Matrix Application

Abstract

The matrix application procedure is the most critical step of thesample preparation procedure, because it affects co-cystalizationof the matrix-analyte complex formed on the tissue surface, thusthe quality of the mass spectra and the subsequent imaging results.Several methods have been used for matrix application: (1) manuallyspraying the matrix solution with a nebulizer sprayer, (2) automaticallydepositing an array of small droplets of matrix solution with roboticdevices, and (3) sublimating the matrices under reduced pressureand elevated temperature. In this chapter, we introduce an overviewof these procedures and then continue with details of technical points,especially of methods (1) and (2). Lastly, a Further advanced applicationmethod, which is the spray-droplet method to increase signal sensitivity,is also described.