Capture Level

Hi All!

I am still very new to using SPR. I was curious about capturing or immobilizing specific levels of protein. Say I wish to capture between 1200-1800 RU. Is there a general rule of thumb on what concentration to use and how long to inject?

Thanks very much for your help.

Hi, welcome.

Depending on the instrument you use you have several options. Biacore type of instruments can aim for the immobilization level in the immobilization method. The system will try to get the immobilization level and in most cases it will succeed. Second option is by hand. First activate the sensor surface and inject the analyte in short pulses until the immobilisation level is reached. Then deactivate.

There is no standard combination between flow rate, ligand concentration and contact time that will give a pre-calculated immobilisation level since this depends also on the nature of the ligand and the activation level of the sensor surface.

This link can be of help.
www.sprpages.nl/immobilization/ligand-pre-concentration

kind regards
Arnoud