Automated, rapid solid-phase proteolytic cleavage and sample preparation for proteomics.

The development of robotic sample preparation systems has allowed the throughput of protein analysis to be accelerated. However, one of the rate-limiting steps in preparing protein samples for analysis by mass spectrometry is their proteolytic cleavage. Robots have been successfully used for the in-gel tryptic digestion of proteins as well as the desalting, concentration, and loading of protein digests onto matrix-assisted laser desorption/ionization (MALDI) targets. The advantages of these instruments are fast and stable sample processing and precise spotting. It seems reasonable to use these advantages for the entire protein sample preparation in a single instrument. In this paper,we describe a method to achieve this goal by performing protein sample concentration, all the digestion chemistry steps, and MALDI target loading on Zip-Tips using a rapid and fully automated method.