How much protein do you need for SEC-MALS?

➢ For the Shodex protein columns 100 µl 1mg/ml protein is a good starting point. Small proteins (< 10kD) give lower light scatter signals and you might have to increase the protein concentration. ➢ Samples should be filtered through a 0.1 µm filter or centrifuged to remove precipitates and larger insoluble particles.

What is SEC-MALS used for?

SEC-MALS determines molecular weight from 200 g/mol to 1 billion g/mol. It can also determine molecular size – the rms radius, or radius of gyration Rg – from 10 nm to 500 nm and beyond. By combining molar mass and size, it can also assess molecular conformation.

What is SEC protein analysis?

SEC is a very effective method for protein analysis and it allows true size profiling of protein samples due to the mild separation conditions that can be used to obtain high-resolution separations. This is a great advantage compared to other size-separation techniques, such as ultrafiltration or dialysis.

Why is there no peak for BSA?

Why are there no peaks for BSA? One reason there are no peaks for BSA might be due to the colorless solution of BSA. The molecule of interest cannot be detected because it is colorless. Another reason might be because BSA binds to smaller molecules, it alters the normal flow rate through the column.

What is MALS detector?

A MALS detector is a type of light scattering measurement system, which allows for the detection of light scattered by components of a solution into multiple distinct angles. Many times MALS detectors are coupled with a separation system, such as FFF or SEC.

What is DLS and SLS?

The evaluation of the fluctuations is commonly named as dynamic light scattering (DLS) while the analysis of the absolute mean intensity is known as static light scattering (SLS). The intensity is very sensitive to variations in size of the solutes, so that it is advantageous to investiagte aggregation in solution.

What is the difference between static and dynamic light scattering?

Dynamic light scattering measures the time-dependent fluctuations in the scattered light intensity which allows the determination of the translational diffusion coefficients (i.e. Brownian motion) and hence particle/molecular size. Static light scattering measured the time-averaged intensity in the scattered light.