On-plate digestion using a commercial microfraction collector for nano-HPLC matrix-assisted laser desorption/ionization tandem time-of-flight protein analysis

Rui Vitorino, Sofia Guedes, Kenneth Tomer, Pedro Domingues, José Duarte, Francisco Amado, Rui Vitorino, Sofia Guedes, Kenneth Tomer, Pedro Domingues, José Duarte, Francisco Amado

Index: Anal. Biochem. 380 , 128-30, (2008)

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Abstract

A new method for on-plate protein digestion and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry analysis is proposed involving an automated one-step sample separation using nanoflow HPLC followed by nanoliter fraction collection and on-plate digestion with trypsin. This procedure uses a commercial automatic nanoliter fraction collection system for on-line spotting of the eluent onto a MALDI target. After protein digestion, the reaction is stopped by the addition of acidified matrix using the same automated system. Collected spots are subsequently analyzed using a MALDI tandem time-of-flight (TOF/TOF) mass spectrometer for protein sequencing and identification.