Electrospray-Assisted Laser Desorption Ionization (ELDI) and Tandem Mass Spectrometry for Proteomic Studies

摘要

Electrospray-assisted laser desorption ionization (ELDI) is a soft ionization method which combines features of both ESI and MALDI. ELDI works under ambient conditions for protein solutions deposited on a sample plate, and produces multiply-charged ions. The ELDI ionization process consists of two separate steps: generation of gaseous neutral (or perhaps charged) molecules by laser desorption, and subsequent post-ionization of the neutral species by ESI. We demonstrate that ELDI-MS from matrix-containing sample droplets is amenable for peptides and proteins, and for the first time, we show that MS/MS spectra of tryptic digests, large peptides, and small proteins can be acquired using ELDI.