Proton high-resolution magic angle spinning NMR analysis of fresh and previously frozen tissue of human prostate

The previously observed improvement in spectral resolution of tissue proton NMR with high‐resolution magic angle spinning (HRMAS) was speculated to be due largely to freeze‐thawing artifacts resulting from tissue storage. In this study, 12 human prostate samples were analyzed on a 14.1T spectrometer at 3°C, with HRMAS rates of 600 and 700 Hz. These samples were measured fresh and after they were frozen for 12–16 hr prior to thawing. The spectral linewidths measured from fresh and previously frozen samples were identical for all metabolites except citrate and acetate. The metabolite intensities of fresh and freeze‐thawed samples depend on the quantification procedures used; however, in this experiment the differences of means were