NEB/SNAPCell® TMRStar/S9105S/30 nmol

Description:

SNAP-Cell® TMR-Star is a red fluorescent substrate that can be used to label SNAP-tag® fusion proteins inside living cells, on cell surfaces, or in vitro. This cell-permeable substrate (CP-6-TMR) is based on the single isomer 6-carboxytetramethylrhodamine and is suitable for standard rhodamine filter sets. It has an excitation maximum at 554 nm and an emission maximum at 580 nm. This package contains 30 nmol of SNAP-Cell TMR-Star substrate, sufficient to make 10 ml of a 3 µM SNAP-tag fusion protein labeling solution.

The SNAP-tag protein labeling system enables the specific, covalent attachment of virtually any molecule to a protein of interest. The SNAP-tag is a small protein based on mammalian O⁶-alkylguanine-DNA alkyltransferase (AGT). SNAP-tag substrates are derivatives of benzylpurines and benzylchloropyrimidines. In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the SNAP-tag.

There are two steps to using this system: subcloning and expression of the protein of interest as a SNAP-tag fusion, and labeling of the fusion with the SNAP-tag substrate of choice. Expression of SNAP-tag fusion proteins is described in the documentation supplied with SNAP-tag plasmids. The labeling of the fusion proteins with the SNAP-tag substrate is described below.

Figure 1:

Figure 2: Excitation (dotted line) and emission spectra of SNAP-Cell TMR-Star after coupling to SNAP-tag in buffer at pH 7.5

Figure 3: Structure of SNAP-Cell TMR-Star (MW 677.1 g/mol)

Notes:

Storage: SNAP-Cell TMR-Star should be stored at -20°C (long term) or at 4°C in the dark (short term, less than 4 weeks). Protect the substrate from light and moisture. With proper storage at -20°C the substrate should be stable for at least three years dry or 3 months dissolved in DMSO.While the majority of SNAP-tag substrates are benzylguanine derivatives, the SNAP-tag is also able to recognize chloropyrimidine derivatives. SNAP-Cell TMR-Star is one such example.