Reversible and irreversible effects of chemical fixation on the NMR properties of single cells.
The effects of chemical fixation are known to alter MR parameters, such as relaxation times and the apparent diffusion coefficient (ADC) of water. It is often assumed that such changes are reversible after samples have been reimmersed in a buffer solution for a sufficient period of time. In this study we characterize the changes associated with fixation of single Xenopus laevis oocytes and their subsequent reimmersion in buffer. Substantial reductions in both T(1) and T(2) values were measured for all compartments of the cell after fixation, with the cytoplasm showing larger changes than the nucleus. After reimmersion in buffer, there were small but statistically significant differences in MR parameters between fresh and reimmersed cells. Experiments with a gadolinium (Gd) contrast agent showed evidence of irreversible changes in the permeability of cellular membranes to small molecules.
Purea
Armin
A
Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany.
Webb
Andrew G
AG
D000704:Analysis of Variance; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D003287:Contrast Media / Q000493:pharmacokinetics; D005557:Formaldehyde / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009865:Oocytes / Q000378:metabolism*; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D016707:Tissue Fixation / Q000379:methods*; D014982:Xenopus laevis
D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D005557:Formaldehyde