Synaptic Systems - GFP sdAb

GFP sdAb - FluoTag-X4 - N0304-AF568-L

A green fluorescent protein tag

This product was developed by

Camelid single domain antibodies (sdAbs) consist only of one antigen binding site of an Alpaca heavy chain antibody. With only ~15 kDa, these Tags are about 10-times smaller than conventional IgG antibody molecules.

Camelid single domain antibody

Background

Green fluorescent protein GFP and its derivates have become very popular and universal tools in cell biology. It is a monomeric and fast maturating protein with high photostability. Due to its sensitivity to pH changes it can be used as a biological pH indicator.

Unlabeled variants and several modifications of sdAbs like biotin, fluorophore or DBCO conjugation are available.

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 (< 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 (in X4 variants) 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 ~ 3 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.

1 ) Hussain A et al., Elife (2018)
2 ) van Roessel P et al., Nat. Cell Biol. (2002)
3 ) Stephens DJ et al., J. Cell. Sci. (2001)
4 ) Chamberlain C et al., Traffic (2000)

Cat. No. N0304-AF568-L	200 µl purified antibody, lyophilized from PBS, fluorescence-labeled with AZdye 568. Albumin was added for stabilization. For reconstitution add 200 µl H₂O. Either add 1:1 (v/v) glycerol, then aliquot and store at -20°C until use, or store aliquots at -80°C without additives. Reconstitute immediately upon receipt! Avoid bright light when working with the antibody to minimize photo bleeching of the fluorescent dye.
Applications	ICC: 1 : 500 FACS: yes
Label	AZdye 568, two fluorophores coupled to two FluoTags each
Clone	1H1/1B2
Immunogen	Recombinant protein corresponding to AA 1 to 238 from jellyfish GFP (UniProt Id: P42212)
Specificity	GFP (green fluorescent protein) and common GFP derivatives like EGFP, mEGFP, Sirius, tSapphire, Cerulean, eCFP, mTurquoise, acGFP, Emerald, superecliptic pHluorin, paGFP, superfolder GFP, eYFP, mVenus, mClover3 and Citrine