Description
Product Usage Information
trFluor™ Europium Cryptate conjugated antibodies are ideal for protein-protein interaction assays, pair-based immunoassay technologies, or high-throughput screening where greater sensitivity and quantitative detection is needed. The long fluorescent decay time of Europium Cryptate results in improved signal to background over fluorescent dye conjugates. Methods utilizing Europium Cryptate conjugated antibodies include, but are not limited to, TR-FRET, where Europium Cryptate-labeled donor antibodies are paired with red fluorophore-labeled acceptor antibodies, such as Alexa Fluor ® 647 or APC. Please contact us if you require an acceptor antibody clone conjugated to a red dye at a custom concentration, a carrier-free formulation, or a more customized packaging solution. Note: Addition of potassium fluoride (KF) in the assay dilution buffer range of 40-400 mM is recommended for enhanced fluorescent signal. Optimal dilutions and working concentrations of both the conjugated antibodies and the KF should be determined by the end user.
Storage
Supplied in PBS (pH 7.2), less than 0.1% sodium azide, and 2 mg/mL BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.
Specificity / Sensitivity
His-Tag (27E8) Mouse Monoclonal Antibody (trFluor™ Europium Cryptate Conjugate) detects recombinant proteins containing the 6xHis epitope tag. This antibody recognizes the 6xHis-tag fused to either the amino or carboxy terminus of targeted proteins in transfected cells.
Species Reactivity: All Species Expected
Source / Purification
Monoclonal antibody is produced by immunizing animals with a 6xHis synthetic peptide.
Background
Epitope tags are useful for the labeling and detection of proteins using immunoblotting, immunoprecipitation, and immunostaining techniques. Because of their small size, they are unlikely to affect the tagged protein's biochemical properties. A variety of plasmids contain DNA that encodes an amino-terminal tag cosisting of six histidine (6xHis) residues followed by an extended multiple cloning site. The 6xHis tag on the expressed recombinant proteins allows for efficient coupling to Ni2+ affinity resins and purification by single step chromatography (1). As is the case with other protein tag systems (2), this polyhistidine tag can often be cleaved at sites recognized by proteases such as thrombin and enterokinases to isolate the protein of interest (1).
