Intracellular mechanical work facilitates multiple cell functions, such as material transport, cell motility, etc., and is indicative of the cell’s physiological condition. Still, the characterization of intracellular mechanical work and resultant dynamics remain hard to determine in intact label-free cells. For that, we imaged live T cells via bright-field microscopy and studied fluctuations in the homogeneity of their intracellular medium. Specifically, we characterized medium homogeneity and dynamics by using the information entropy of its related intensity gray levels (termed Gray Level Information Entropy (GLIE)) and spectral analysis of GLIE fluctuations, respectively. First, we provide simple examples of particle motion, to demonstrate the utility of our approach. Using this approach, we could further study and distinguish mitochondrial dysfunction and ATP depletion state in live Jurkat cells. The relation of our results to intracellular dynamics was confirmed by comparison to image correlation spectroscopy (ICS) results in the same cells. Importantly, GLIE fluctuations combined with spectral analysis enabled differentiation of malignant Jurkat cells from benign lymphocytes with 86% accuracy for single cells and 95% for populations of 10 cells each. Our approach can serve for label-free live-cell study and diagnostics of important pathophysiological conditions, such as mitochondrial dysfunction and malignancy.
Bibliographical noteFunding Information:
Funding: This research was funded by the ISF, grant number 1761/17.
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
- Image processing
- Information entropy
- Medium homogeneity
- Spectral analysis