Updated project metadata. Defining the in vivo proteomes of specific cell-types in the central nervous system of mammals, without ex vivo manipulation, is an important and outstanding challange. Here we demonstrate that stochastic orthogonal recoding of translation (SORT) can be used to tag the proteomes of specific cell types in brains of live mice. We tag neuronal proteomes from the striatum and perform enrichment before identifing neuronal proteins by LC-MSMS.