SEC-SAXS Experiments

SEC-SAXS experiments are the gold standard experiment for high quality monodisperse data. A typical protein SEC-SAXS sample is 50 µL at 1-10 mg/ml, with 500 mL of buffer usually shipped a 10x stock.
 

Buffers will be optimised to stabilise the sample. Including 1-2% glycerol or sucrose helps reduce radation damage. Including some salt (i.e. 100-150 mM) will help reduce interation between the particle and the column and inter-particle correlation effects that could reduce data quality. Detergents/lipids can form higher order structures that can interact with the sample and are best avoided.

There are some things to consider when planning your SEC-experiment:

• Column Equilibration: It takes an hour to equilbrate the column. It is possible to switch buffers/ use multiple columns but this should be taken into consideration when planning your experiment. We can equilibrate 2 columns at a time.

• Running of the standard, BSA : When planning your experiment you must allow one BSA run per column used to ensure the column is working effectively. Each BSA run should take 30 minutes.

• Sample number: Each sample for SEC-SAXS takes 32 minutes, therefore you must plan in advance how many samples it will be possible to run in your allocated time.