Hello,
I've recently done an spr experiment with a protein as ligand and four different peptides as analyte to check for the relative affinity in each case. to check for the reproducibility, i repeated the exact same experiment. pattern of curves in both the case were reproduced, but the range of response unit was completely different. although the capture of the ligand protein was shown to be less in the second exp compared to the first exp, the response units for all four analyte showed an increase in the second experiment. dissociation constant values are dissimilar too in both the experiments. help anyone?