The ability to discriminate between single cells in a label-free and noninvasive fashion is important for the classification of cells, and for the identification of similar cells from different origins. In this paper,...The ability to discriminate between single cells in a label-free and noninvasive fashion is important for the classification of cells, and for the identification of similar cells from different origins. In this paper, we present the Raman spectroscopy-based identifi- cation of different types of single cells in aqueous media, and discrimination between the same types of cells from different donors using a novel Laser Tweezers Raman Spectroscopy (LTRS) technique, which combines laser trapping and micro-Raman spectroscopy. First, we measured the spectra of individual living human erythrocytes, i.e. red blood cells, and leucocytes (U937 cancer cells). High-quality Raman spectra with low fluorescence were obtained using a home-LTRS apparatus and 20 cells were measured for each cell type. The smoothing, baseline subtraction, and normalization of the data were followed by a principal components analysis (PCA). The PCA loading plots showed that the two different types of cells could be completely separated based only on the first component (PC1) (i.e. the peaks at 1300 cm1 ); the discrimination accuracy could therefore reach 100%. More than 50 spectra were taken for each erythrocyte obtained from the four healthy volunteers. The average discrimination accuracy was 84.5% for two random individuals taken from the four volunteers, according to the first and second PCs. This work demonstrates that LTRS is a powerful tool for the accurate identification and discrimination of single cells, and it has the potential to be applied for the highly sensitive identification of cells in clinical diagnosis and medical jurisprudence.展开更多
We investigate the activation of living monocytic U937 cells induced by interleukin-6 （IL-6） at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and w...We investigate the activation of living monocytic U937 cells induced by interleukin-6 （IL-6） at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and without IL-6 at the single cell level. Raman peaks of amide III, amide I, DNA backbone, as well as guanine and adenine in U937 cells, change at 1312, 1652, 1090, and 1576 cm ？1 , respectively, shortly after IL-6 is added in the medium. The change is a dynamic temporal process. In the activation process of U937 cells induced by IL-6, the protein signals recover in 20 min, while the nucleic acid signals continue to increase for 20 min. The results reveal that the biochemical cascades of activation in signal transduction induced by IL-6 can be investigated in situ at the single cell level.展开更多
The present study aimed at identifying cell cycle inhibitors from the fermentation broth of Streptomyces pseudoverticillus YN17707. Activity-guided isolation was performed on ts FT210 cells. Compounds were isolated th...The present study aimed at identifying cell cycle inhibitors from the fermentation broth of Streptomyces pseudoverticillus YN17707. Activity-guided isolation was performed on ts FT210 cells. Compounds were isolated through various chromatographic methods and elucidated by spectroscopic analyses. Flow cytometry was used to evaluate the cell cycle inhibitory activities of the fractions and compounds. Two compounds were obtained and identified as pteridic acid hydrate(1) and pteridic acid C(2), which arrested the ts FT210 cells at the G0/G1 phase with the MIC values being 32.8 and 68.9 μmol·L-1, respectively. These results provide a basis for future development of Compounds 1 and 2 as novel cell cycle inhibitors for cancer therapy.展开更多
基金Project supported by the National Natural Science Foundation of China for Distinguished Young Scholars （No. 39825126）, the 973-project from Ministry of Science and Technology （No. 1998051113）, and the Fund for Cheung Kong Scholar from the Cheung Kong Scholars Program of Minis- try of Education of China.
Acknowledgments We thank Prof. Q. Sun and Mrs. G. Qu, both of Shenyang Pharmaceutical University, China, for their contributions on the collection and identification of the plant materials. Dr. H. 0sada, head of the Antibiotics Laboratory, the Institute of Physical and Chemical Re- search （RIKEN）, Japan, kindly provided the tsFT210 cell line.
基金supported by Beijing Natural Science Foundation(5102019)National Science and Technology Infrastructure Program(2012BAF14B14)
文摘The ability to discriminate between single cells in a label-free and noninvasive fashion is important for the classification of cells, and for the identification of similar cells from different origins. In this paper, we present the Raman spectroscopy-based identifi- cation of different types of single cells in aqueous media, and discrimination between the same types of cells from different donors using a novel Laser Tweezers Raman Spectroscopy (LTRS) technique, which combines laser trapping and micro-Raman spectroscopy. First, we measured the spectra of individual living human erythrocytes, i.e. red blood cells, and leucocytes (U937 cancer cells). High-quality Raman spectra with low fluorescence were obtained using a home-LTRS apparatus and 20 cells were measured for each cell type. The smoothing, baseline subtraction, and normalization of the data were followed by a principal components analysis (PCA). The PCA loading plots showed that the two different types of cells could be completely separated based only on the first component (PC1) (i.e. the peaks at 1300 cm1 ); the discrimination accuracy could therefore reach 100%. More than 50 spectra were taken for each erythrocyte obtained from the four healthy volunteers. The average discrimination accuracy was 84.5% for two random individuals taken from the four volunteers, according to the first and second PCs. This work demonstrates that LTRS is a powerful tool for the accurate identification and discrimination of single cells, and it has the potential to be applied for the highly sensitive identification of cells in clinical diagnosis and medical jurisprudence.
基金supported by the National Natural Science Foundation of China (No. 10674008)the Beijing Natural Science Foundation (No. 5102019)
文摘We investigate the activation of living monocytic U937 cells induced by interleukin-6 （IL-6） at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and without IL-6 at the single cell level. Raman peaks of amide III, amide I, DNA backbone, as well as guanine and adenine in U937 cells, change at 1312, 1652, 1090, and 1576 cm ？1 , respectively, shortly after IL-6 is added in the medium. The change is a dynamic temporal process. In the activation process of U937 cells induced by IL-6, the protein signals recover in 20 min, while the nucleic acid signals continue to increase for 20 min. The results reveal that the biochemical cascades of activation in signal transduction induced by IL-6 can be investigated in situ at the single cell level.
基金supported by the National Natural Science Foundation of China(No.30472079)National Basic Research Program of China(No.2006CB504100)
文摘The present study aimed at identifying cell cycle inhibitors from the fermentation broth of Streptomyces pseudoverticillus YN17707. Activity-guided isolation was performed on ts FT210 cells. Compounds were isolated through various chromatographic methods and elucidated by spectroscopic analyses. Flow cytometry was used to evaluate the cell cycle inhibitory activities of the fractions and compounds. Two compounds were obtained and identified as pteridic acid hydrate(1) and pteridic acid C(2), which arrested the ts FT210 cells at the G0/G1 phase with the MIC values being 32.8 and 68.9 μmol·L-1, respectively. These results provide a basis for future development of Compounds 1 and 2 as novel cell cycle inhibitors for cancer therapy.
