Matrix-Assisted Laser Desorption/Ionisation - time of flight mass spectrometry (MALDI - TOF MS) has become an essential tool for the analysis of biomolecules. It has near-universal applications in the analysis of compounds including proteins and peptides, nucleic acids and oligonucleotides, carbohydrates, natural products, synthetic polymers and more.

Accurate molecular weight information can be determined in minutes using extremely small quantities of complete cells or fractions of further purification steps. The matrix, a low weight organic acid, is mixed with the analyte solution and prepared on the template. The p-electrons absorb the laser photons (nitrogen laser giving a 337 nm output) and the matrix with the analyte molecules is desorbed. The ions are accelerated with a voltage of 20 kV and are detected after 1.2 meters of flight path on the detector.