Introduction to MALDI and its applications in protein and peptide analysis. Including the principle of MALDI, the analysis methods of MALDI, the advantages and disadvantages of MALDI
This document presents a technical comparison between the Agilent AP-MALDI ion source equipped on an LC/MSD Trap SL system and two commercial vacuum MALDI-TOF instruments. The study focuses on analyzing tryptic digests of proteins such as cytochrome c, lysozyme, myoglobin, and bovine serum albumin (BSA) at the femtomole level.
The results indicate that the Agilent AP-MALDI Trap system demonstrated superior signal-to-noise ratios compared to the vacuum MALDI-TOF systems. Additionally, the document highlights the advantage of generating true MS/MS data for peptide sequencing using the ion trap technology, which is not possible with standard reflectron TOF systems. The analysis also covers spectral similarities and differences, noting that AP-MALDI produces fewer low-mass ions due to softer ionization at atmospheric pressure.
AP-MALDI-IT decouples ionization factors from mass accuracy, permits true MS/MS data generation for peptide sequencing even at subfemtomole levels, and allows switching between modes in minutes.
The system enabled peptide analyses in the 250-500 attomole level, which is significantly below levels attained using many vacuum MALDI-TOF instruments.