Single-cell Analysis Methods Based On Optical Tweezers Raman Spectroscopy

Raman spectrum is a kind of simple and sensitive new technique for spectrum analysis which had a quick development in cell's structure, function and cell apoptosis in recent years. Currently, the Raman spectrum have got an extensive application in agriculture, industry, chemistry, life sciences and so on, acquire obvious effect. But towards a few of cells or large biomolecular which is swim by Brownian motion , using the common Raman spectrum instrument to collect its Raman spectrum will very difficult, So we adopt a laser tweezers-Raman spectroscopy system, it is a new tool to study the molecule structure of organism tissue.The spectrum technique of the optical Raman tweezers for the single cell is combined of optical trapping and Raman spectroscopy which is a new technique applying in research of suspending cell in solution. Its principle is using a focused laser beam, permit the capture of a live cell in solution, which can stay in the laser trap sufficiently long, a large Raman signal from the trapped cell is permitted since the cell is trapped in the focus of the excitation beam, which permits optimum excitation and collection for Raman scattering in confocal configuration. Applying the technique of optical Raman tweezers in research of single cell and the diagnosis of thalassemia and cancer is a very meaningful job.Thalassemia is a set of hereditary hemolytic diseases caused by the globin chain synthesize obstacle which was induced by imperfection or blemish of mammaglobin gene.Among them,αandβ-Thalassemia are the most prevalent disease. For long time, the thalassemia perplexs millions of people living in south of china, and southeast of Asia. In GangXi. In some area ,α-Thalassemia incidence rate is 15%, is higher than any other province, andβ-Thalassemia incidence rate is 5%. Thalassemia examination and molecular biology's study(include a blood normal regulations examination, hemoglobin(Hb) electrophoresis analysis, Hb A2 and Hb F measurement, DNA analysis etc.) all is according to the macroscopic average result of a great deal of cell in the blood .The above-mentioned laboratory examination's method should cost a lot of money , the operation is tedious, moreover,the workload is very heavy, So it isn't suit for the check in big area crowd. Applying the Raman spectroscopy of the laser tweezers to the single-cell for the research of thalassemia , probably provide a kind of new research method and research angle, which can announce to public the hemoglobin abnormality in layer of single-cell caused by thalassemia.In the meantime, Raman spectrum is a kind of fast, simple, valid method to check and diagnose thalassemia, possessing good academic value and clinical application foreground. Through the usage of Raman spectroscopy of the laser tweezers, can discover abnormal structure of Hb molecular in single red cell's lever, and these abnormality are coverd by macroscopical average. In the meantime, this text research expressed: recur to apply pricipal component analysis to Raman spectrum, theα-Thalassemia(HbH) and theβ-Thalassemia(major) can be quickly diagnosed by single-cell's Raman spectrum.Because the cancer's earlier symptom isn't obviously, and the diversity of symptom is very similar to some familiar diseases, so it is very difficult to discover in time.Currently, the diagnosis of the cancer mainly use the cytology authenticate of tumor slice as gist, however, the non- quantity diagnosis process of pathologic is greatly tedious, and very subjective. Therefore search a method to diagnosed cancers in early period which is convenience, fast, and no wound is significantly. The difference of normal organize and pathological changed organize can be reflected in chemistry constitutes and molecule structure at molecule lever by using Raman spectrum, so may become an approach that diagnoses tumor in earlier period .Our research discovered that the spectrum strength of normal man's liver cells were obviously weaker than the liver cancer cells, and exist some obvious differences.In this paper, based on some data which obtained by a laser tweezers-Raman spectroscopy system, mainly use the algorithms of pattern recognition and data contrast, carry on analysis with the Raman spectrum data obtained from thalassemia cells and liver cancer cell, in order to find out a suitable method to classify these Raman spectrum data of different disease efficiently. Then put forward a method to collect Raman spectrum, which can obtain certain sample's spectrum data quickly, and improve the quality of the data efficiently. So we provided a new way of thinking for the full-automatic method to collect the spectrum data.According to the work do by author, the text was divided into three parts to carry on introduction. Algorithms of pattern recognition for identifying thalassemia. In this part, a classifier is designed to distinguish two different types of thalassemia, using the 785 nm laser beam of Raman spectrum with optical tweezers. After the original data are preprocessing, PCA is used for data analyzing and feature extracting. Then an artificial neural network is trained to classify the different illness. Some experiments are conducted and demonstrate that our method for identifying thalassemia is efficient and promising.Applies optical Raman tweezers to the diagnosis of liver cancer. This chapter introduced a technique to obtain Raman spectrum of liver cancer cells and normal liver cells by a laser tweezers-Raman spectroscopy system,then carried on the analysis of experiment result.The combination of microfluidic chip and Raman spectroscopy system . In this paper, at last, we will introduce a way which will combine the microfluidic chip of the cell electrophoresis and a laser tweezers-Raman spectroscopy system to obtain the raman spectrum form person's red cell. Combine the experiment result and a traditional way to obtain the Raman spectrum from single cell and carry on the contrast analysis, discover this technique will speed the progress which the Raman spectrum obtained from the cell consumedly, and have no obvious influence to the experiment result.