What is Rmax in SPR?

Rmax is determined by the relative molecular weight ratio between ligand and analyte and the amount of immobilized ligand. If the interaction is not 1:1 the Rmax is also determined by the binding stoichiometry.

Is KD concentration dependent?

The rate constants ka, kd and the equilibrium constant KD is independent of the concentration of both analyte and ligand but is dependent on the pH, salt, temperature and pressure of the solution.

How does a Biacore work?

Biacore systems monitor the interaction between two molecules, of which one is attached to the sensor surface and the other is free in solution. A sensorgram is a plot of response against time, showing the progress of the interaction.

What is a low Kd value?

– Low affinity: Kd larger than 10-4 (> 100 microM) – Moderate affinity: Kd between 10-4 and 10-7 (100 microM – 100 nM) – High affinity: Kd smaller than 10-7 (< 100 nM) However, people working on in different fields may have different considerations.

What does a high Kd value mean?

So a higher Kd means that when you go take a molecular census, there are more unbound molecules, whereas a lower Kd means that you find more bound molecules.

How do you find theoretical Rmax?

1. Desired Theoretical Rmax = (MWanalyte/MWligand) x [Immobilized Ligand (RU) x % of theoretical Rmax] x Stoichiometry 2. Desired Theo. Rmax = 150 = (30/150) x Immobilized Ligand (RU) x 0.82 x 2 3.

Is higher or lower Kd better?

The KD value relates to the concentration of antibody (the amount of antibody needed for a particular experiment) and so the lower the KD value (lower concentration) and thus the higher the affinity of the antibody.

What is a good Kd value?

Thus, a Kd of 10-6 (1 microM) can be considered as high affinity in metabolism regulation, while it can be considered a low affinity in antibody design. And this is related to another way to judge the strength of an interaction which takes into account the potential concentrations of the interacting molecules.