I would like to now why I find this small oscillations in the beginning of the curves for the high concentration of analyte (500 uM and 1 mM) in the sensorgram. the protein is on the chip and the small molecule is injected (in the same running buffer). The stock of the small molecule was in 100% DMSO.
The experiment was done in a Biacore T200 at 25C.
Running buffer : 10 mM HEPES pH 7.4, 150 mM NaCL, 0.05% Tween.
Small molecule dilution:Running buffer plus 5%DMSO (1mM), 2.5%DMSO (500 uM), 1,25 (250 uM) and go on. Could be these peaks have a DMSO origin?
Looking at the picture I suspect that there is a significant DMSO buffer jump in the original curves, am I right?
In addition the channels are in series which means that the buffer jump is not exactly at the same time. And when subtracting this negative of positive jumps can occur.
You can try to align the curves better or to try to minimize the buffer jumps (best option).