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RFP sdAb - FluoTag-X4 - N0404-At542-L

A red fluorescent protein tag


This product was developed by   


FluoTags are camelid single domain antibodies consisting only of one antigen binding site of a Alpaka heavy chain antibody. With only ~15 kDa, these Tags are about 10-times smaller than conventional IgG antibody molecules.

Single Domain

Cat. No.: N0404-At542-L
Amount: 200 µl
Price: 485.00 €
Cat. No. N0404-At542-L

200µl 2.5µM camelid sdAb in buffered saline, 50% glycerol, 0.09% sodium azide

Storage Up to three months: -20°C
Up to 12 months: -80°C or below
Protect form light!
Applications WB: not recommended
ICC: 1 : 250 gallery  
IHC: not tested yet
IHC-P/FFPE: not tested yet
Label ATTO 542, two fluorophores coupled to two FluoTags each
Clone 2B12-2A1
Immunogen Recombinant protein corresponding to AA 1 to 225 from sea anemone RFP (UniProt Id: Q9U6Y8)
Specificity Recognizes most common red fluorescent proteins like mRFP, mCherry, dsRed 1/2 and tdTomato.
Does not cross-react with GFP or mTagBFP derivatives.
Documents data sheet

Cat. No.: N0404-At542-L
Quantity: 200 µl
Price: 485.00 €

Red fluorescent protein RFP is a common fusion protein used in cell biology to follow the localization and expression of proteins of interest. RFP is known for its rapid maturation and high resistance to photobleaching and therefore well suited for multi color imaging.


In FluoTag-Q each fluorophore is coupled to exactly one FluoTag, which in turn binds to its target molecule in a monovalent fashion. The high binding affinity and a coupling efficiency of > 95% guarantees a highly linear relation between the number of target molecules and the intensity of fluorescence. This enables a direct count of the target molecule of interest. The fluorophore is located exceptionally close to the recognized epitope (less than 1.5 nm), which is ideal for all microscopy techniques.

In FluoTag-X two fluorophore molecules are site-specifically coupled to each FluoTag molecule. Therefore, the reagent simultaneously targets up to four fluorophores to the protein of interest, which ensures extra-bright signals. Owing to the small size of the FluoTags, the distance between the target epitope and each fluorophore is below 4 nm.
In comparison to detection systems using conventional antibodies, FluoTag-X can thus improve the localization accuracy by 10-15 nm. Both features - superior brightness and precise fluorophore placement - render the FluoTag-X products excellent tools for all microscopy techniques.