Microimaging of oxygen concentration near live photosynthetic cells by electron spin resonance.
We present what is, to our knowledge, a new methodology for high-resolution three-dimensional imaging of oxygen concentration near live cells. The cells are placed in the buffer solution of a stable paramagnetic probe, and electron spin-resonance microimaging is employed to map out the probe's spin-spin relaxation time (T(2)). This information is directly linked to the concentration of the oxygen molecule. The method is demonstrated with a test sample and with a small amount of live photosynthetic cells (cyanobacteria), under conditions of darkness and light. Spatial resolution of approximately 30 x 30 x 100 microm is demonstrated, with approximately microM oxygen concentration sensitivity and sub-fmol absolute oxygen sensitivity per voxel. The use of electron spin-resonance microimaging for oxygen mapping near cells complements the currently available techniques based on microelectrodes or fluorescence/phosphorescence. Furthermore, with the proper paramagnetic probe, it will also be readily applicable for intracellular oxygen microimaging, a capability which other methods find very difficult to achieve.
Halevy
Revital
R
Schulich Faculty of Chemistry Technion, Israel Institute of Technology, Haifa, Israel.
Tormyshev
Victor
V
Blank
Aharon
A
D002138:Calibration; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology*; D012996:Solutions; D046939:Synechocystis / Q000166:cytology* / Q000378:metabolism*
D012996:Solutions; D010100:Oxygen