Air spikes in curves
The origin of (air)spikes in the sensorgrams can be of different origin.
Air spike can for instance originate from the running buffer. When this buffer is not degassed properly small air bubbles can build up inside the injection system eventually crossing the sensor surface. Even when using an instrument with a degasser, the samples are not degassed. If you find spikes during the injection phase only, degas the buffer used for the analyte dilution.
The analyte itself can induce spikes by aggregating in solution or on the sensor surface. To remove aggregates from the analyte spin the sample for 5 minutes at 15000g.
When you find spikes during the flow and analyte injection or dissociation phase this is an indication that the instrument need some thorough cleaning. If after cleaning the spikes persist, the detection system has to be (professionally) cleaned.
Spikes at the beginning and ending of the association phase are mostly induced by large buffer differences between running buffer and sample. Especially after subtracting a reference channel high bulk effect differences can cause these spikes. The best remedy is to change the buffer of the sample to match the running buffer.