SNAP-Cell® 430 is a blue 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 (BG-430) is based on diethylaminocoumarin and is suitable for appropriate blue lasers and filter sets. It has an excitation maximum at 421 nm and emission maxima at 444 and 484 nm. This package includes 50 nmol of SNAP-Cell 430 substrate, sufficient to make 10 ml of a 5 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 human 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: sub-cloning 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: Live CHO-K1 expressing nuclear histone H2B-SNAP (H2B-SNAP) were labeled with SNAP-Cell™ 430 (aqua).Figure 2: Excitation (dotted line) and emission spectra of SNAP-Cell 430 coupled to SNAP-tag in buffer at pH 7.5Figure 3: Structure of SNAP-Cell 430 (MW 513.5 g/mol).
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Storage: SNAP-Cell 430 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.
