Updated PubMed. We developed a simple and sensitive analysis method for dried blood spot (DBS) proteins by sodium carbonate precipitation (SCP). We aimed to removing large amounts of hydrophilic blood proteins such as hemoglobin, albumin, fibrinogen and transferrin in DBS using a simple pretreatment with sodium carbonate solution, which concentrates membrane proteins. We evaluated the performance of the SCP method by comparing the LC-MS/MS results obtained for proteins prepared by SCP with those obtained by sodium dodecanate (SoDod) extract as total protein solubilized from DBS.