SiR-tetrazine

SiR-tetrazine is a clickable derivative of SiR. This probe reacts with dienophiles such as trans-cyclooctene (TCO) or bicyclononyne (BCN) derivatives, enabling the preparation of custom SiR probes and conjugates. SiR-tetrazine is particularly useful in combination with unnatural amino acid (UAA) incorporation to prepare site selective protein conjugates. SiR-tetrazine is cell permeable and fluorogenic, it can be used to stain live cells as well as fixed ones. SiR is compatible with GFP and/or m-cherry fluorescent proteins. It can be imaged with a standard Cy5 filterset.