Dried Blood Spots samples are a rich source of proteins and have therefore great potential for proteomics biomarker discovery studies. Only a few articles have used DBS samples for non-targeted bottom-up protein analysis, probably due to the complexity of the DBS samples. Gas-phase separation by ion mobility spectrometry such as Field Asymmetric Waveform Ion Mobility (FAIMS) could be useful in analysis of DBS samples as FAIMS has previously shown to be advantageous for bottom-up protein analysis of complex samples. The aim of this project was therefore to evaluate FAIMS in non-targeted analysis of Dried Blood Spots.