A method for measuring cytoplasm viscosity based on quantum dot three-dimensional tracing

Abstract

A method for measuring cytoplasm viscosity based on quantum dot three-dimensional tracing is disclosed. The method includes firstly introducing quantum dots into cells through a lipid Lipo-2000 transfection manner to achieve cell labeling; subjecting the single and recognizable quantum dots dispersed in the cells to three dimensional positioning and tracing by adopting an optical modulating mannerthrough a build quantum dot three-dimensional imaging system; further solving mean square displacement values MSDs which are motion parameters of the quantum dots by utilizing three-dimensional motion information; selecting quantum dots meeting free diffusion characteristics according to mathematical characteristics of the MSDs; finally solving diffusion coefficient D of the quantum dots in cytoplasm according to the MSD values for all the quantum dots meeting free diffusion characteristics; and further acquiring the cytoplasm viscosity according to a Stokes-Einstein equation. In a state thatcells survive, the cytoplasm viscosity can be accurately acquired by the method, visual three-dimensional motion information of molecules in cytoplasm can be obtained, and technical bases for researching intracellular material transportation, signal transmission, metabolism, differentiation, and the like are provided.

Description

technical field [0001] The invention belongs to the technical field of micro-nano three-dimensional imaging, and in particular relates to a method for measuring cytoplasmic viscosity based on quantum dot three-dimensional tracing. Background technique [0002] Cytoplasm is the main site of cell life activities, and is the general term for all translucent, gelatinous, and granular substances surrounded by the cytoplasmic membrane except the nuclear region. The viscosity of the cytoplasm is the main factor affecting the diffusion of biomolecules. By obtaining the viscosity value of the cytoplasm, we can further understand important processes such as material transport, signal transmission, metabolism and differentiation in living cells. The current method for determining the viscosity of cytoplasm is to use a viscometer to measure the viscosity of cytoplasm by extracting the cytoplasm. However, after the cytoplasm is extracted from the cell body, its characteristics in the ce...

AI Technical Summary

Problems solved by technology

At present, scholars have used it as a probe of intracellular viscosity to reflect the value of cell viscosity through fluorescence intensity changes, fluorescence anisotropy and fluorescence lifetime, but this method cannot intuitively understand the three-dimensional motion characteristics of molecules under specific cytoplasmic viscosity

In order to obtain the three-dimensional motion characteristics of molecules in the cytoplasm, real-time positioning and tracking technology of quantum dots is involved. At present, this technology is mostly for positioning in two-dimensional systems. Although common three-dimensional confocal scanning microscopes and tomographic scanning microscopes can perform three-dimensional positioning of quantum dots, However, it is necessary to scan the sample, which is not suitable for real-time tracking of quantum dots in cells

Images