Water suppression without signal loss in HR-MAS 1H NMR of cells and tissues.
In cell and tissue samples, water is normally three orders of magnitude more abundant than other metabolites. Thus, water suppression is required in the acquisition of NMR spectra to overcome the dynamic range problem and to recover metabolites that overlap with the broad baseline of the strong water resonance. However, the heterogeneous cellular environment often complicates water suppression and the strong coupling of water to membrane lipids interferes with the NMR detection of membrane associated lipid components. The widely used water suppression techniques including presaturation and double pulsed field gradient selective echo result in more than a 70% reduction in membrane associated lipid components in proton spectra of cells and tissues compared to proton spectra acquired in the absence of water suppression. A water suppression technique based on the combination of selective excitation pulses and pulsed field gradients is proposed to use in the acquisition of high resolution MAS NMR spectra of tissue specimens and cell samples. This pulse sequence methodology enables efficient water suppression for intact cells and tissue samples and eliminates signal loss from cellular metabolites.
Chen
Jin-Hong
JH
Sarcoma Disease Management Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Sambol
Elliot B
EB
Kennealey
Peter T
PT
O'Connor
Rachael B
RB
DeCarolis
Penelope L
PL
Cory
David G
DG
Singer
Samuel
S
D001834:Body Water / Q000737:chemistry; D006801:Humans; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009369:Neoplasms / Q000737:chemistry*; D014407:Tumor Cells, Cultured / Q000737:chemistry
D006859:Hydrogen