Hello @MARKBOND. It isn’t necessarily required to check for the expression of full-length fusion proteins. We don't do this every time that we develop a new assay. Typically we go right into our optimization experiments of testing the different combinations in order to find the best performing pair using the strategy outlined in section 3 of the tech manual. Can you share a little about the assay you are developing? Do you have a tool compound or known modulator?
However, we do know that many researchers would like to confirm that they are expressing the full-length fusion to ensure that nothing unusual happened during the cloning. Especially if any troubleshooting is required during assay development. If you have primary antibodies against your proteins you will see a size shift for the LgBiT fusion, but the SmBiT fusion can be difficult to distinguish . We are currently working on antibody development. We do not yet have an antibody for SmBiT. However, we do have a polyclonal raised against NanoLuc that also recognizes LgBiT. Would you like an aliquot of this? Just let me know and we can get one out to you. Or let us know if there is additional support we can provide.