Current NMR Strategies for Biomarker Discovery - Proteomic and Metabolomic Approaches to Biomarker Discovery - page 94

FIGURE 2 The downfield spectral expansions of mouse urine from (A) wild-type mouse 1D 1 H NMR spectrum, (B) wild-type mouse 2D TOCSY, and
(C) Abcc6-knockout mouse 2D TOCSY. The 2D data show a wealth of information not obtainable from the 1D data. Statistically signi cant peaks from the

PLS-DA models without log transformation are circled in orange, and those from log transformed data are colored green for increase in wild-type mice
and purple for increase in knockout mice. The open circles indicate corresponding regions for better visualization. The combined use of 2D NMR data and
log transformation detected contributions from the less abundant metabolites responsible for group separation, most of which were not detectable using
1D 1 H data. (Reprinted with permission from reference #36. Copyright 2011 American Chemical Society.)