The effect of sample freezing on proton magic-angle spinning NMR spectra of biological tissue

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DOI

  • David A. Middleton
    SmithKline Beecham Pharmaceuticals
  • Daniel P. Bradley
    SmithKline Beecham Pharmaceuticals
  • Susan C. Connor
    SmithKline Beecham Pharmaceuticals
  • P G Mullins
    SmithKline Beecham Pharmaceuticals
  • David G. Reid
    SmithKline Beecham Pharmaceuticals

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 1H 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.

Keywords

  • Animals, Culture Techniques, Disease Models, Animal, Freezing, Kidney, Magnetic Resonance Spectroscopy, Protons, Rats, Rats, Sprague-Dawley, Reference Values, Reproducibility of Results, Comparative Study, Journal Article
Original languageEnglish
Pages (from-to)166-9
Number of pages4
JournalMagnetic Resonance in Medicine
Volume40
Issue number1
DOIs
Publication statusPublished - 1 Jul 1998
Externally publishedYes
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