Method for measuring and calculating height conversion coefficient of magnetic tweezers under small force and application

Abstract

The invention provides a method for measuring and calculating the height conversion coefficient of magnetic tweezers under small force, which comprises the step of measuring and calculating the heightconversion coefficient of the magnetic tweezers by using a nucleoprotein filament formed by combining homologous recombinant protein and DNA as an absolute scale and according to the height difference before and after the nucleoprotein filament is formed and the base number of the DNA. The invention further provides application of the method. Calculation of the conversion coefficient is an important link of instrument correction and has a very important position, and recalibration needs to be carried out after instrument accessories, an objective lens and an objective lens are replaced, oil immersion is performed and a light path is adjusted. According to the invention, the cost and environmental noise required by instrument construction can be reduced, and the purpose of quickly and simply measuring and calculating the coefficient is achieved.

Description

technical field [0001] The invention relates to the technical field of single-molecule biophysics, in particular to a method and application for measuring and calculating the conversion coefficient of the height of magnetic tweezers under small force. Background technique [0002] Magnetic tweezers are a common method for studying single-molecule biophysics, and the research objects are usually biological macromolecules such as DNA, RNA, and proteins. In the study, one end of the biomacromolecule was attached to a paramagnetic bead and the other end was attached to a coverslip. The shape of the diffraction ring of the magnetic ball is different with the change of the height in the solution. Through the shape of the diffraction ring of the magnetic ball, we can get its position in space. At the same time, through the control of the magnetic field gradient, the force exerted by the magnet on the paramagnetic sphere can be changed, and then the force acting on the biomacromole...

AI Technical Summary

Problems solved by technology

However, the limitation of this method is that it needs to use a higher magnetic force, and the data in a strong environment is required to make the fitting result the most accurate, and the strong condition needs to reduce the slit spacing of the magnet, resulting in a decrease in the amount of light passing through, and a more expensive one has to be replaced. High power LED light source

A high-power light source will increase the cost of many instruments. In addition, its heat dissipation will affect the reaction system. A fluctuation of 0.1°C will cause 5nm environmental noise to the instrument.

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