This project used a custom-built capillary electrophoresis (CE) mass spectrometry (MS) platform to demonstrate the scalable analysis of proteins from single cells of varying sizes and protein content in different vertebrate biological models. Neural tissue fated giant cells were identified in cleavage-stage Xenopus laevis (frog) embryos, and 18 ng from its protein content was analyzed. From cultured primary neurons from the mouse, diluted samples containing ~125 pg of protein digest was measured, estimating to a portion of the somal protein content. Compared to traditional nano-flow liquid chromatography (nanoLC) MS, CE-MS provided higher sensitivity and faster analysis. CE-ESI-HRMS offers a viable approach for scalable single-cell proteomics.