CLIP-Cell™ Block (bromothenylcytosine, BTC) is a non-fluorescent compound that blocks the reactivity of the CLIP-tag™ in vitro and inside or on the surface of living cells. It can be used to generate inactive controls in live cell labeling experiments performed with CLIP-tag fusion proteins. BTC reacts with CLIP-tag irreversibly, inactivating it for subsequent labeling steps.
The CLIP-tag protein labeling system enables the specific, covalent attachment of virtually any molecule to a protein of interest. CLIP-tag is a protein tag based on human O6-alkylguanine-DNAalkyltransferase (hAGT). CLIP-tag substrates are derivatives of benzylcytosine (BC). In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the reactive cysteine of CLIP-tag forming a stable thioether bond. Although CLIP-tag is based on the same protein as SNAP-tag®, the benzylcytosine substrates form a separate class of substrates, different from the benzylguanine substrates recognized by SNAP-tag. CLIP-tag and SNAP-tag can be used for orthogonal and complementary labeling of two proteins simultaneously in the same cells.
There are two steps to using this system: subcloning and expression of the protein of interest as a CLIP-tag fusion, and labeling of the fusion with the CLIP-tag substrate of choice. The use of BTC during the labeling of fusion proteins with CLIP-Cell substrates is described in this document.
Legal and Disclaimers
Cellular Imaging and Analysis (i.e., SNAP and CLIP products)
The products and/or their use may be covered by one or more of the following patents and patent applications:
7,939,284 (Methods for Using O6-Alkylguanine-DNA-Alkyltransferases)
7,888,090 (Mutants of O6-Alkylguanine-DNA-Alkyltransferases)
8,163,479 Specific Substrates for O6-Alkylguanine-DNA-Alkyltransferases)
8,178,314 (Pyrimidines Reacting With O6-Alkylguanine-DNA-Alkyltransferases)
PCT/EP2007/057597 (Labeling of Fusion Proteins with Synthetic Probes)
EP07117800 (Drug Delivery)
EP07117802 (Drug Delivery)
EP07120288 (GTPase-Transient Protein Protein Interactions)
These patents and patent applications are owned by Covalys, or owned by the Ecole Polytechnique Fédérale de Lausanne (EPFL) and exclusively licensed to Covalys and NEB.