Hi, there, thank you so much for this website. I leaned a lot from here.
I started to learn Biacore about 3 months ago, last week, first time I got a negative results.
Protein to protein: The analyte binds to reference line (cell1) at -580RU; binds to active line (cell 2) at -540RU; then cell2-1’s binding activity is -40RU. I lower the concentration of the sample (from 1uM to 0.5uM), the activity was increased to -20RU. The method including flow rate and running buffer is followed by a published paper. I never saw this kind of binding before, do you have any idea about this negative results?
I also using different analyte, the results come out as normal.
It seems like an buffer mismatch. Do you dilute the analyte in the running buffer?
What happens when you inject just running buffer? Is the baseline then flat?
Can you give the instrument and post an figure as an example?