Radioligand - Saturation Assay Help! - (Jun/04/2012 )

I want to do a saturation assay using a single conc of protein and varying conc of radioligand.

I'm sure how to vary the radioligand conc without changing the radioactivity. (i.e. I need 190Bq/10 ul for each conc). Do I dilute with unlabelled ligand? How does this affect binding and the cpm/dpm I can measure????

you dilute the labelled ligand so that it can be pipetted comfortably. you add unlabelled ligand to attain the desired concentrations for each sample.

as unlabelled concentration increases, binding of labelled ligand decreases.