The biochemist's penchant for grinding and fractionating can have the unfortunate consequence of destroying protein complexes—ultimately distorting our view of how proteins are organized and regulated in the cell. On page 676, Link et al. describe a new proteomics tool that alleviates this problem by making it possible to identify each component of large macromolecular complexes containing more than 100 proteins. Their system combines multidimensional liquid chromatography and tandem mass spectrometry to separate and fragment peptides with an algorithm to infer amino acid sequences from peptide masses.