This project tested the use of a volumemetric absorptive microsampling device as a substrate to prepare whole blood for proteomic analysis by LC-MS. We demonstrated that VAMS are a useful substrate to trap proteins from blood, wash them to reduce highly abundant protein species which enabled single shot LC-MS. This led to the detection of more than 1600 proteins in a single run. We further tested different washing reagents and compared VAMS against paper DBS. Finally, we demonstrated an application of using VAMS to prepare archival, frozen whole blood cell pellets from non-small cell lung cancer patients for biomarker studies.