FAQ: What is the smallest peptide and biggest protein you have cloned as SNAP-tag fusions?

Smallest: The SNAP-tag has been expressed as a fusion with various short signal sequences, such as CaaX (4 amino acids, part of a farnesylation sequence), GPI anchor signal sequence (30 amino acids) or 3x NLS (24 amino acids) and correctly localized to the plasma membrane or to the nucleus as appropriate.
Biggest: SNAP-b-galactosidase (141 kD), enzymatic activity verified by a colorimetric assay.