Often the most important part of a nanobody discovery project is confirming that the nanobody binds to the native protein expressed on the cellular surface of a protein. Abcore can screen single domain antibodies for this important functionality using flow cytometry.
Abcore uses flow cytometry to test for functional binding of the nanobodies and depending on the target we can also use flow cytometry to establish an EC50 (half maximal effective concentration) of the nanobodies. This helps to rank positive sequences, but does not establish the actual affinity, on-rate, or off-rate. However, when we generate a large list of positive sequences from a project, this is a very important way that we can rank the positives, to select a subset to move forward with further testing