Optical scatter imaging of programmed cell death

Optical Scatter Imaging (OSI) was recently developed in our laboratory to study subcellular morphological changes in viable cells. The process utilizes Fourier filtering and the ratio of wide-to-narrow angle scatter intensity (OSIR) to detect alterations in the size of particles with wavelength-scale dimensions. In the present study, we utilize OSI to track subcellular changes during programmed cell death. OSI showed an average 21% decrease in OSIR. The OSIR initial was 183.8 +/- 7.2 and the OSIR final was 145.9 +/- 4.3, p < 0.001, n=57 (mean +/- 95% confidence interval of the mean) upon induction of cell death by 1μM of the kinase inhibitor staurosporine. This decrease was not observed in cells that over expressed Bcl-x, an anti-apoptotic protein localized on the mitochondria. Combining OSI with genetic manipulations provides a novel approach and tool, with which to study apoptosis, a fundamental biological process.