Optimization of Raman spectra acquisition conditions and its application in a comparison study on mesenchymal stem cells and embryonic stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Raman spectrum, compared with conventional detection technologies, is a rapid, non-invasive and label-free optical method. Its application has become an issue of concern in biomedical research. However, further studies are warranted to optimize the acquisition condition of Raman spectra from different stem cells. OBJECTIVE: To explore the effect of the wavelength of laser and the groove frequency of gratings to obtain the optimized parameter combination for Raman spectrum collection in human stem cells. METHODS: Using human mesenchymal stem cells as samples, the effects of different laser wavelengths (532, 38,785 nm) and different grating groove frequency (600, 1200, 1800 gr/mm) on Raman spectra were compared respectively. Then the different combinations of the wavelength and groove frequency were used and compared in terms of the spectra resolution and acquisition time, and the best acquisition condition was selected and applied in a comparison study on the Raman spectra from human mesenchymal stem cells and human embryonic stem cells. RESULTS AND CONCLUSION: The wavelengths of lasers and groove frequencies of gratings showed compound impacts on both the spikes at different wavenumbers and the ratio between spikes; the combination of 785 nm and 1200 gr/mm was confirmed to be the best spectrum features for human mesenchymal stem cells. The comparison of Raman spectra from human mesenchymal stem cells and human embryonic stem cells implies that the embryonic stem cells contain higher nucleic acids than the mesenchymal stem cells, while the mesenchymal stem cells appear to contain more proteins and lipids.