| Laser tweezers Raman spectroscopy (LTRS) is a biological photonic technology that is the combination of optical trap technique with Raman spectroscopy and applied to study suspension cell. Raman spectroscopy, which offers a noninvasive, nondestructive, fast, and water-insensitive technique, is widely applied in biology and medicine. Raman technique is suitable for biological macromolecules, cells etc, with aqueous solution. Optical tweezers can trap a cell. Raman tweezers utilize a focused laser to form the gradient force for trapping living cell in the optical trap. LTRS technique not only eliminates adverse effects caused by common micro-Raman technique because cells must fix on slide, but also obtains a higher signal noise ratio (SNR).Liver cancer has become the third most malignant tumors, second only to gastric cancer, esophageal cancer, but early symptoms are not obvious. Therefore, the detection of liver cancer has been as an important issue of the current medical research. But applying LTRS technology on hepatocellular carcinoma, Raman spectroscopy information has not been obtained totally, because liver cancer cells have larger diameter. In this work, we explore Raman spectra of single hepatocellular carcinoma for their bio-molecules distribution, and the characteristic peak area of the band at 786,1450 and 1658 cm-1, which are assigned to DNA, lipid and protein are extracted. Then, the images based on the peak area after normalization are reconstructed, according to Raman spectra which is acquired from the scanning location in liver cell. The results show that, the distribution of DNA, lipid and protein can be exhibited by this Raman mapping system, and the reliability is validated by the fluorescence staining. The research results can be an important reference in developing Raman diagnostic method for primary hepatocellular carcinoma.Red blood cell is an important component of human blood. Erythrocytes are the most in the blood cells. And erythrocytes play a very important role in metabolism and gas transportation for human body. The structure and function of red blood cells provide insights into the oxygen carrying capacity of red blood cells, even blood diseases, pathology, diagnosis and treatment of red blood cells to provide a theoretical basis related diseases. LTRS study of red blood cells have demonstrated the unique advantages, but in vivo studies on red blood cells are rare. In this work, laser tweezers Raman spectroscopy on the blood vessels in live mice ear to study red blood cells, red blood cells obtained previously in vitro study do not draw some important conclusions. The main conclusions are as follows:Raman spectroscopy is used to study red blood cells and blood in vein capillary, in artery capillary in vivo and in vitro with the use of optical tweezers. Results show that,1. we can get Raman spectroscopy of blood in vivo,2. we can observe clearly that different blood spectroscopy in oxygenated and deoxygenated state in artery and vein capillary.3. by studying Raman spectroscopy of single RBC, we conclude that the hemoglobin concentration in capillary is larger than that in vitro, and oxygenated Raman peak of RBC in artery capillary is more obvious than those in vein capillary.4. by comparing Raman spectrum in vein and that in artery, we find that pH value in artery capillary is higher than that in vein capillary, and by studying the change of the band at 1604 cm-1, we find that the band change is in connection with the circumstance pH value around RBCs. These findings may make it possible to study conformational changes within single cells in vivo. Our experiments also have shown that laser tweezers Raman spectroscopy can provide a strong tool for research in vivo. |
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