The effect of sample freezing on proton magic-angle spinning NMR spectra of biological tissue
The effect of sample freezing on proton magic-angle spinning NMR spectra of biological tissue
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DOI：
10.1002/mrm.1910400122
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发表时间：
1998-07-01
影响因子：
3.3
通讯作者：
Reid, DG
中科院分区：
文献类型：
--
作者：
Middleton, DA;Bradley, DP;Reid, DG
Magic-angle spinning (MAS) has recently been shown to enhance spectral resolution in NMR examinations of intact biological tissue ex vivo. This work demonstrates that freezing certain tissue samples before examination by H-1 MAS NMR can have a marked effect on their spectra. Spectra of rat kidney after freezing in liquid nitrogen, compared with spectra before freezing, showed a significant increase in signal intensities from alanine (> 100%), glutamine (> 40%), and glycine (> 100%), and a decrease in signals assigned to lipids and other macromolecules. Some resonances-such as from leucine, valine, isoleucine, and aspartate-only became visible after freezing the tissue. These observations suggest that low temperature storage of tissue necropsies or biopsies might affect the results of a MAS NMR analysis, possibly resulting in the misinterpretation of metabolite changes to pathogen or disease effects.
