The OLLAS (E.coli OmpF Linker and mouse Langerin fusion Sequence) epitope tag is a new, highly sensitive tag.  The OLLAS epitope tag has been shown to be detectable at approximately 100-fold lower levels that similar commercially available tags using the OLLAS monoclonal antibody, including Sigma's anti-FLAG^® epitope tag antibody. The OLLAS tag has also been demonstrated to provide superior functionality whether used as an N-terminal, C-terminal, or internal tag on recombinant and fusion proteins without interfering with the biological activity of the tagged protein.