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Shin-ichi Morita, having a class

Shin-ichi MORITA, Associate Professor 

experienced optical measurements and spectral analysis
at chemistry (7 years), physics (6 years), and biology (4 years)
joined this laboratory (bio-analytical chemistry), Dec. 2013
published, so far, ~40 papers


【Our Direction】To Realize Optical Measurements of Small Molecules in Live Cells [as Analytical Chemistry]
With Several Years,to Biology Research [in Science]

Here, in this laboratory, we focus on bio-Raman research (research on live cells using Raman microscopes).

Recently it became possible to measure Raman spectra of a single live cell using a standard Raman microscope. Bio-molecules such as proteins, nucleic acids, lipids, etc., that is, atoms combined with electrons, vibrate with different wavenumbers. These oscillators interact with the light, and are detected as Raman scattering. Using Raman signals, we are capable of, for instance, analyzing the distribution of bio-molecules. Also, many killer applications were opened. It is however difficult to distinguish the Raman bands of similar molecules. Raman analysis, therefore, is ambiguous and complicated. Plus, bio-Raman data is extremely large.

An idea sketch to begin

【Disentangling of Complicated Large Data】 is of our interest, in this respect. For instance, Raman spectral data of live cells is complicated and large, especially when we observe the time intervals of cellular differentiation (typically several days). It is almost impossible to understand those data in an intuitive manner. Spectral analysis is, therefore, essential to extract and visualize intrinsic information. We have developed mathematically analytical methods compatible to bio-Raman research.

【Use of Raman-Tagged Small Molecules】is another promising approach of purifying our scientific interest. Let us assume that we introduce large fluorescent chromophores as markers to small molecules such as lipids and some of nucleic acids. Far from giving original properties, target small molecules are perturbed by larger labels. Therefore, dot-like Raman probes such as alkyne-tags are expected to be effective markers even for small molecules. We are developing Raman tags, for instance, utilizing the resonance Raman effect to enhance the brightness of molecular emissions. We are also interested in developing Raman markers sensitive to surrounding environments.

【Development of a Bio-Raman Microscope】, we are trying this mainly in order to monitor the dynamics of cellular differentiation, proliferation, and apoptosis. To do so, living cells have to be incubated on the microscope stage for several days; plus, the positions of moving cells have to be confirmed continuously. Using the bio-Raman microscope, it is possible to define cellular states in a non-destructive and non-labeling manner. Based on the information of cellular conditions, we are expecting to control cellular destinies. Raman monitoring is probably effective for tissue engineering.

For instance,

◾S. Morita, S. Takanezawa, M. Hiroshima, T. Mitsui, Y. Ozaki, Y. Sako
"Raman and Autofluorescence Spectrum Dynamics along the HRG-induced Differentiation Pathway of MCF-7 Cells"
Biophysical Journal, 2014, 107: 2221–2229.

◾S. Takanezawa, S. Morita, Y. Ozaki, Y. Sako
"Raman spectral dynamics of single cells in the early stages of growth factor stimulation"
Biophysical Journal, 2015, 108(9): 2148-2157.

【Running of the Symposium】