Use of advanced mass spectrometry techniques in the undergraduate setting has burgeoned in the past decade. However, relatively few undergraduate experiments examine the proteomics tools of protein digestion, peptide accurate mass determination, and database searching, also known as peptide mass fingerprinting. In this experiment, biochemistry students digest a protein mixture from egg white using the enzyme trypsin; liquid chromatography electrospray ionization time-of-flight mass spectrometry (LC--ESI-TOF-MS) separates the resulting peptides and determines their accurate masses. Instrument software is used to match these peptides to the sequences of known egg white proteins, obtained from an online source. Students then use online protein database search software to match the peptides to the protein and score the results.