Phase-sensitive two-dimensional experiment on living animals

This report describes the first 1H-1H phased spectrum obtained in vivo from the hind-leg muscles of an intact mouse. TOCSY correlations can follow the complete spin system and give a more detailed graph of each molecule than can COSY. TOCSY is also better suited than COSY for studying long fatty-acid chains. All the peaks are in phase in a TOCSY experiment and the intensities of the cross-correlation peaks are less sensitive to low digitalization in the t1 domain than are those of COSY. The improvement in sensitivity was estimated by measuring the volumes of the cross-correlation peaks in COSY and TOCSY spectra.