MALDI MS is Matrix-assisted laser desorption/ionisation Mass spectrometry is widely used for analysis of structural analysis and for identification and characterisation. They are used in the analysis of post translational modifications for their protein-protein interactions in small and large molecules enabling direct analysis of biological samples from cell and tissue homogenates. Here the molecules are not fragmented, they are analysed intact. The molecules to be analysed are mixed with organic/chemical molecules called matrix, that absorbs energy, converts to heat and the sample is analysed and exploded into mass analyser. The matrix absorbs ultra violet light converting it to heat. Smaller part of the matrix is also heated and vaporised with the sample. This technique analyses peptide bio markers and biological molecules in the tissues and compared with the other proteins.