February 12, 2015 at 4.00 pm in AG-80
Single Molecular Spectroscopy of Single Live Cell
The 2014 Nobel Prize in Chemistry has been awarded for the development of Single Molecule Spectroscopy. We will discuss some recent application of this technique to the study of a single live cell. In a confocal microscope, the size of the focused spot (~200 nm = 0.2 m) is one-hundredth of the dimension of a cell. Thus one can probe different regions/organelles in a cell. Utilizing this, we will describe several new phenomena inside a live cell [1-5]. Specifically, we have discovered found substantial differences between a cancer cell and a normal cell [1-4]. The gold nano-clusters preferentially enter or stain a cancer cell compared to a non-malignant cell . The red-ox processes (thiol-disulfide interconversion) lead to intermittent structural oscillations leading to fluctuations in fluorescence intensity in a single live cell [2-3]. Such oscillations are absent for a cancer cell . The number of lipid droplets are much higher in a cancer cell. We detected stochastic resonance during gene silencing in a cancer cell .
1. S. Chattoraj, et al. "Fluorescent Gold Nano-Cluster inside a Live [UTF-8?]Cell,â€ J. Phys. Chem. C 118
(2014, in press).
2. S. Chattoraj, et al. "Role of Red-Ox Cycle in Structural Oscillations and Solvation Dynamics in Mitochondria,"
J. Phys. Chem. B 118 (2014, in press).
3. S. Ghosh, et al. "Solvation Dynamics and Intermittent Oscillation of a Cell Membrane: " J. Phys. Chem. B 118
4. R. Chowdhury, et al. "Confocal Microscopy of Cytoplasmic Lipid Droplets in a Live Cancer Cell”
Med. Chem. Comm. 5 (2014) 536-539.
5. S. Chattoraj, et al. "Dynamics of Gene Silencing in a Live Cell," J. Phys. Chem. Lett. 5 (2014) 1012-16.