Synaptic Systems - GFP sdAb

GFP sdAb - N0305-Biotin

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. N0305-Biotin	250 µg purified antibody, lyophilized from PBS, labeled with Biotin. Biotin is a small vitamin B complex molecule. Its small size minimizes interference with antibody binding sites and allows for efficient conjugation without compromising antibody functionality. Biotin conjugated antibodies can be easily detected with Avidin/Streptavidin based secondary detection systems. The streptavidin-biotin bond is one of the strongest non-covalent biological bonds known. Albumin was added for stabilization. For reconstitution add 250 µl H₂O to get a 1mg/ml solution in PBS. Then aliquot and store at -20°C to -80°C until use. Antibodies should be stored at +4°C when still lyophilized. Do not freeze!
Applications	ICC: yes FACS: yes Immunocytochemistry (ICC) on 4% PFA fixed cells. Immunoreactivity is usually revealed by fluorescence. Some antibodies require special fixation methods. For details, please refer to the “Remarks” section. Fluorescence-activated cell sorting (FACS); usually cells are fluorescently labeled with antibodies against cell-surface antigens followed by cell-sorter analysis.
Label	biotin
Clone	1H1
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