Dynamic Light Scattering Analysis of Protein Molecular Weight

In biochemical research, gaining a profound understanding of the structure and function of proteins is of paramount importance. Among these, the measurement of protein molecular weight is a fundamental aspect. This paper will introduce a method for determining protein molecular weight based on Dynamic Light Scattering (DLS).

 

Dynamic Light Scattering (DLS)

Dynamic Light Scattering, also known as size-exclusion chromatography, is a non-invasive method of measurement that can determine the size, shape, and molecular weight of particles. These particles can be of various types such as small molecules, large molecules, proteins, polymers, particles, and others. DLS uses a laser to illuminate the sample, and by measuring the intensity fluctuations of the scattered light, the diffusion coefficient of the particles can be obtained, which in turn provides the size and molecular weight of the particles.

 

Protein Molecular Weight Determination

1. Sample Preparation

Firstly, the protein is dissolved in an appropriate buffer, and subjected to sonication to eliminate suspended impurities and bubbles.

 

2. DLS Measurement

The solution sample is placed in a DLS instrument for measurements. During the measurement process, a correlation function is generated from the fluctuations in the intensity of the scattered light over time.

 

3. Data Analysis

Through mathematical processing, the correlation function is converted into a distribution of particle sizes or particle diffusion coefficients, and further, the Stokes-Einstein equation yields the hydrodynamic radius and molecular weight of the particles.

 

Applications

DLS has widespread applications in biotechnology and drug development. For example, DLS can provide information about new vaccines, antibody drugs, or protein complexes, including their stability, aggregation state, etc. This information is crucial for drug development and quality control.

 

In summary, Dynamic Light Scattering is a very practical method for determining protein molecular weight. It has the advantages of a wide measurement range, high sensitivity, and easy operation. In biochemical research and industrial applications, DLS has become an indispensable tool.