Two Dimensional Correlation Analysis of Raman microspectroscopy of subcellular interactions of drugs in vitro.

Two dimensional correlation analysis is explored to data mine the time evolution of the characteristic Raman microspectroscopic signatures of the subcellular responses of the nucleoli of human lung cancer cells to the uptake of doxorubicin. A simulated dataset of experimental control spectra, perturbed with systematically time-dependent spectral changes, constituted by a short term response which represents the initial binding of the drug in the nucleolus, followed by a longer term response of the organelle metabolism, is used to validate the analysis protocol. Applying two dimensional correlation analysis, the in phase, synchronous correlation co-efficients are seen to contain contributions of both response profiles, whereas they can be independently extracted from the out of phase, asynchronous correlation co-efficients. The methodology is applied to experimental data of the uptake of doxorubicin in human lung cell lines to differentiate the signatures of chemical binding and subsequent cellular response. This article is protected by copyright. All rights reserved.