Overview

Matrix-assisted laser desorption ionization (MALDI) is a mass spectrometry ion source ideal for the analysis of biomolecules. Instead of ionizing compounds in the gaseous state, samples are embedded in a matrix, which is struck by a laser. The matrix absorbs the majority of the energy; some of this energy is then transferred to the sample, which ionizes as a result. Sample ions can then be identified using a time-of-flight analyzer (TOF).

This video covers principles of MALDI-TOF, including matrix selection and how TOF is used to elucidate mass-to-charge ratios. This procedure shows the preparation of a MALDI plate, the loading of samples onto the plate, and the operation of the TOF-mass spectrometer. In the final section, applications and variations are shown, including whole-cell analysis, characterization of complex biological samples, and electron spray ionization.

Procedure

Matrix-assisted laser desorption ionization (MALDI) is a mass spectrometry ion source ideal for the analysis of biomolecules. Instead of ionizing compounds in the gaseous state, samples are embedded in a matrix, which is struck by a laser. The matrix absorbs the majority of the energy; some of this energy is then transferred to the sample, which ionizes as a result. Sample ions can then be identified using a time-of-flight analyzer (TOF).

This video covers principles of MALDI-TOF, including matrix selection and how TOF is used to elucidate mass-to-charge ratios. This procedure shows the preparation of a MALDI plate, the loading of samples onto the plate, and the operation of the TOF-mass spectrometer. In the final section, applications and variations are shown, including whole-cell analysis, characterization of complex biological samples, and electron spray ionization.