MALDI stands for Matrix-Assisted Laser Desorption/Ionization. It is a technique used in mass spectrometry that allows the analysis of large biomolecules such as proteins, peptides, and nucleic acids. MALDI is widely used in biological research and clinical diagnostics due to its ability to identify and characterize molecules based on their mass-to-charge ratio.
In MALDI, the sample to be analyzed is mixed with a matrix material, typically an organic compound, which forms a crystalline substance when dried. This matrix protects the sample molecules and helps to desorb and ionize them upon laser irradiation. The sample-matrix mixture is then deposited onto a metal plate or target.
A pulsed laser is used to irradiate the sample-matrix mixture, causing the matrix molecules to absorb the laser energy and vaporize, subsequently desorbing and ionizing the analyte molecules. The resulting ionized molecules are accelerated and detected by a mass spectrometer, which separates them based on their mass-to-charge ratio and generates a mass spectrum.
MALDI provides several advantages over other ionization methods. It is relatively simple and efficient, allowing for fast and high-throughput analysis of complex biomolecules. It also allows for the analysis of non-volatile and labile compounds that are difficult to ionize by other techniques. MALDI has revolutionized the field of proteomics, enabling the identification and analysis of proteins and peptides in various biological samples.
In summary, MALDI is a mass spectrometry technique that uses a matrix material and laser irradiation to desorb and ionize large biomolecules for analysis. It has become an essential tool in biological and biomedical research, enabling the identification and characterization of complex molecules.
