In light of problems currently being experienced with our BIAcore (perfect detection on Fc2 no signal on Fc1) would it be possible to use a separate chip as a reference surface (i.e. 2 individual chips on Fc2 coupled with the Ligand, second chip Fc2 coupled with BSA or activated/deactivated NHS/EDC) for subtraction and non-specific binding along with double referencing (buffer injections)?
Reason for this is that it would probably take another month for a new IFC to arrive (we can host a world cup but we can't get deliveries within same week, don't ask I can't explain it either).
The point of a reference cell is that it is in line with your sample and thereby exposed to the same buffer, analyte and regeneration conditions. Even when using the same buffers etc. possibly there will be differences in experimental conditions so the reference will not be perfect when using an second chip.
It is it worth a try in your case, but make sure you validate your results. Keep as many variables the same.