Rmax RelResp terminology

Hi I just wanted some clarification on what the Rmax point is really a measure of and what the proportion that get's "stuck" on the ligand is termed. Is this the Relative binding response? i.e. what needs regeneration to remove it.

e.g. I pass antibody (analyte) over antigen (ligand)

The Rmax point in the sensogram is a few seconds before the injection stops to inject buffer and induce dissociation (correct?)

BUT what gets stuck on the surface/ligand and remains until regeneration occurs what is this response termed.

if i had 4 samples of purified IgG for example from 4 perons and i tested them against antigen/ligand X coated on the sensor chip

If person number 3 has the greatest amount of analyte stuck to the ligand at stay 1 minute after dissociation vs person 1,2,4 at teh same timepoit they would have greater affinity antibodies yes? this is like what an ELISA measures? would this mean they also had a higher Rmax (signal just before injection stops)

what would be a better report point Rmax or the bound response to compare these persons or is it the same thing?

Thanks for your help, just trying to clarify this!!

Thanks again

Rmax is the maximal response that is reached when all ligand molecules are occupied by an analyte. Thus you assumption is not correct.
The response at the end of analyte injection I would mark as Rt (response at time t).

When you have four different antibodies, they have likely also four different kinetic constants. Thus the association and dissociation rates will differ. You want to compare the antibodies on binding strength. Affinity ranking is best done with the dissociation phase because this determines how stable the interaction is.
It is not clear if you inject for each purified antibody the same concentration. The analyte concentration determines the response at the end of the injection but this is not a good indication of the strength of the interaction. It is better to fit the dissociation rate because it is independent of the analyte concentration and independent on the amount of bound antibody.

What you can do is take a point 10 seconds after the injection end and one at the dissociation end (say after 5 minutes) and calculated the response difference.

The ELISA signal is an end point signal and when the incubation steps are long enough (generally 1 hour or longer) the signal is measured at steady state (equilibrium) and thus the signal is proportional to the sample concentration. ELISA's are generally done with antibodies with a very slow dissociation rate.