Hello. What is an acceptable value for regeneration? Ideally you would want to go back to the same level before the capture/binding and after. See sensorgram below. It seems like it is going up. In my last injection..it is about 75 RU compared to the beginning. I am using 10mM Glycine pH 1.7 for this experiment....about 45 sec contact time.
Yes, Ideally you want to go back to the baseline at the beginning of the sensorgram. However, surface performance in equally important! So not only back to baseline, but is the ligand still active after regeneration.
To check for this, I inject a know concentration for three times and regenerate in between. The curves should be equal and the baseline return to 'zero'.
Sometimes we find a higher or lower baseline but a good performance of the ligand. In my opinion thats allright.
Regeneration times should be short. Say 5 - 15 seconds. If you have very long regeneration injection times you must look for a better solution for regeneration.