Nonlinear Interferometric Vibrational Imaging for fast, label-free identification of molecular domains in tissue 
Wladimir A. Benalcazar
Beckman Institute Graduate Fellow. Bioimaging Science and Technology Department.

Nonlinear Interferometric Vibrational Imaging, a technique developed at the Beckman Institute, has been used to spatially map the most prevalent molecular constituents of skin. Raman-like profiles over the range from 2800 to 3000 cm^-1 were acquired by means of completely suppressing the coherently mixed non-resonant background, proper of nonlinear processes. This has allowed the generation of images based on the molecule-specific spectral profiles, such as in spontaneous Raman or FT-IR microspectroscopy, but with higher spatial resolution and orders of magnitude, which could further enhance the potential for diagnosis of diseases, especially at early stages of development.

Refractive Index as Maker for Disease
Zhuo Wang
Research assistant in the Department of Electrical & Computer Engineering

Using spatial light interference microscopy (SLIM), an optical imaging method that combines phase contrast microscopy and holography, we rendered the refractive index maps of unstained histopathology slides to a quantitative color-coded image, which is further proved to report onsite of the carcinomas for prostate biopsies and calcifications for breast biopsies. The imaging signatures of SLIM report different properties of the tissue and cells compared to the gold standard of stained histopathology, which relies on a subjective practice and sensitive to variations in the fixation and staining processes. The spatial correlations of refractive index indicate that cancer progression significantly alters the tissue organization. Refractive index is an intrinsic marker for cancer diagnosis and our preliminary results show a sensitivity and specificity that approach 100%.