Figure 1From: Metabolic labeling of plant cell cultures with K15NO3 as a tool for quantitative analysis of proteins and metabolitesMass spectra of the peptide ALGVDTVPVLVGPVSYLLLSK in protein extracts form unlabeled cells (A), 15N-labeled extracts (B), and in mixtures of unlabeled and labeled extract at a ratio of 1:1 (C), a ratio of 1:4 (D), a 4:1 ratio (E). The expected mass to charge ratios of unlabeled and labeled peptides are indicated by arrows.Back to article page