Over the years, scientists and researchers have put their interest on the cellular level of living organisms. They have been trying to understand how cells are interacting in different environments. In order to do so, many techniques has been developed to observe the behavior of living cells. Recently, some techniques are able to obtain in-vivo images of the target cells, allowing scientists to get a new level of information. However, those techniques requires staining of the targeted cells with a compound (FLIM) or the resolution of the techniques does not provide constructive information.
In the last few years, non-linear optical measurements used in conjunction with microscopy observations, have created new opportunities of research and technological achievements in the field of life sciences. Second-order nonlinear processes such as second-harmonic generation (SHG), and third-order processes such as third-harmonic generation (THG), coherent anti-Stokes Raman scattering (CARS), Stimulated Raman Scattering (SRS) and two-photon excited fluorescence (TPEF) have been employed for the imaging and the understanding of biological systems and processes.
The nonlinear imaging techniques represent the forefront of research in cell biology. These modalities comprise a powerful tool for elucidating structural and anatomical changes of biological samples and for probing functions and developmental processes in vivo at the microscopic level. Consequently, the investigation of in vivo cellular and sub-cellular activities, by means of these non linear imaging techniques, can provide valuable and unique information related to fundamental biological problems, leading to the development of innovative methodologies for the early diagnosis and treatment of several diseases.
Genia Photonics has developed a fiber laser based solution ( Picosecond programmable Synchronized Laser System for biomedical imaging) that allows the user to generates CARS signals. Combining this technology to a microscope or an endoscope, one can then visualize the targeted cells in vivo. Moreover, one main advantage of Genia’s solution is that it nullifies the non resonant background hence providing a higher resolution images. Genia’s laser system not only allows to perform nonlinear imaging but can also be used as a source for other imaging techniques such as Optical Coherent Tomography (OCT).
Hyperspectral Images Using CARS:*
(a) Mouse ear in DMSO @ 1560nm (b) Mouse ear in DMSO @1560-1575nm (c) Polybeads images @1570nm
*taken at Université Laval, Québec.