Single-cell MALDI: a new tool for direct peptide profiling

Matrix-assisted laser desorption-ionization (MALDI) mass spectrometry (MS) is a rapid and sensitive analytical approach that is well suited for obtain ing molecular weights of peptides and proteins from complex samples. MALDHM S can profile the peptides and proteins from single-cell and small tissue s amples without the need for extensive sample preparation, except for the ce ll isolation and matrix application. Strategies for peptide identification and characterization of post-translational modifications are presented. Fur thermore, several recent enhancements in MALDHMS technology, including in s itu peptide sequencing as well as the direct spatial mapping of peptides in cells and tissues are discussed.