Study Of Two-dimensional Light-scattering Flow Cytometer Based On Sheath Flow Technology

Light scattering technology has played an important role in cell and particle analysis with its advantage of label free,high speed,harmlessness and high accuracy.Traditional cell biology observes cells under a microscope,by studying the morphological characteristics of cells or cells labeled with dyes.Study of cells usually requires statistical analysis of a large number of samples,which could be time-consuming and arbitrary upon using conventional methods.It's very important to realize the automated rapid detection,thus the flow cytometer came across.The traditional flow cytometer collects only one dimensional(ID)light scattering signals and the fluorescence signals,while the two-dimensional(2D)light-scattering patterns obtain rich information of cells(such as size,shape,volume and internal structure)in a label-free manner.Therefore,the study of 2D light scattering flow cytometer has great significance for the research and diagnosis of cells.In this thesis,by combining the 2D light scattering technology with microfluidic technology,we developed a 2D light scattering flow cytometer that is based on sheath flow technology,which can obtain the 2D light scattering patterns from a single standard microsphere or a single cell in flow.This is very important for the development of methods and instruments for automatic,high-speed and high-accuracy cell analysis,especially for the development of novel flow cytometer.Firstly,this thesis gave a brief introduction of the light scattering theory for the development of the instrument.The classical Mie theory was used to study the 1D light scattering of standard microsphere and was extended to the 2D cases.Then the sheath flow technology was described briefly.This thesis focused on the development of a new type of 2D light scattering flow cytometer,and solved the technique issues of measuring 2D light scattering patterns of single microsphere in a microfluidic flow.Finally,a new type of label-free flow cytometer was integrated.Our results demonstrated that the 2D light-scattering flow cytometer based on sheath flow technology can be used to distinguish submicron spheres with a high-resolution.The work done in this thesis could be useful for the development of 2D light-scattering flow cytometer to realize high-throughput cellular analysis.