Indirect immunostaining of PFA fixed Hela cells expressing Nup98-GFP with FluoTag®-X4 Atto 565 anti-GFP sdAb (Cat. No. N0304, dilution 1:500, the GFP signal is represented in green, the corresponding FluoTag®-signal is represented in red and the merge of both channels is represented in yellow).

FluoTag-X4 anti-GFP AF647

PFA-fixed Cos7 cells expressing a TOM70-nfGFP-BFP fusion protein (nf: non-fluorescent) were stained with FluoTag®-X4 anti-GFP coupled to Alexa Fluor 647 (Cat. No. N0304-AF647, dilution 1:500). A Greyscale image of the staining performed with N0304-AF647. B False color representation of the image shown in A is displayed in magenta (coloring according to the excitation wavelength of the employed fluorophore). C The corresponding BFP signal of the depicted section. D Merge of A and C. False color representation of A in magenta and C in blue.

FluoTag-X4 anti-GFP AF568

PFA-fixed Cos7 cells expressing a TOM70-nfGFP-BFP fusion protein (nf: non-fluorescent) were stained with FluoTag®-X4 anti-GFP coupled to AZDye568 (Cat. No. N0304-AF568, dilution 1:500). A Greyscale image of the staining displayed with N0304-AF568. B False color representation of the image shown in A is presented in red (coloring according to the excitation wavelength of the employed fluorophore). C The corresponding BFP signal of the depicted section. D Merge of A and C. False color representation of A in red and C in blue.

FluoTag-X4 anti-GFP At488

PFA-fixed Cos7 cells expressing a TOM70-nfGFP-BFP fusion protein (nf: non-fluorescent) were stained with FluoTag®-X4 anti-GFP coupled to Atto 488 (Cat. No. N0304-At488, dilution 1:500). A Greyscale image of the staining performed with N0304-At488. B False color representation of the image shown in A is displayed in green (coloring according to the excitation wavelength of the employed fluorophore). C The corresponding BFP signal of the depicted section. D Merge of A and C. False color representation of A in green and C in blue.

FluoTag®-X4 anti-GFP

Cat No: N0304 Category:


FluoTag®-X4 anti-GFP is a blend of two in-house developed single-domain antibodies (sdAbs) that recognize two distinct epitopes on GFP and its most common derivatives with high affinity and specificity.

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General information

A breakthrough in biology and bioluminescence began in the 60s with the discovery of a glowing protein obtained from the jellyfish Aequorea victoria by Osamu Shimomura and colleagues. However, it was only in the early 90s when the green fluorescent protein (GFP) sequence was cloned and used inside a foreign organism as a fluorescent marker. Today more than 800 entries of various fluorescent proteins can be found in an open-source database with the most currently available variants in the fluorescence protein database “fpbase”

Our sdAbs bind strongly to most of the fluorescent proteins derived from Aequorea Victoria; check our specificity chart in our Resource Section.

For detailed information regarding our FluoTag-Q, -X2, and -X4 series check our Technology Section.

Conjugation Amount Cat No. RRID
Atto488 200 μl N0304-At488-L AB_2744629
AZDye568 200 μl N0304-AF568-L AB_3075903
Atto643 200 μl N0304-At643-L AB_3075906
Alexa647 200 μl N0304-AF647-L AB_2905517
AbberiorStar635P 200 μl N0304-Ab635P-L AB_3075902
Related Products:

sdAb anti-GFP HRP (cat. no. N0305-HRP)

sdAb anti-GFP Biotin (cat. no. N0305-Biotin)


Clone: 1H1, 1B2
Host: Alpaca
Produced in: E.coli
Application: IF
Dilution: 1:250 (corresponding to 5 nM for each sdAb clone)
Capacity: N/A
Antigen: -
Targets: GFP
Specificity: Recognizes 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 and Citrine.
Formulation: A mixture of two sdAb clones lyophilized from PBS pH 7.4 containing 2% BSA (US-Origin). Reconstitute with 200 µL of 50 % glycerol in deionized water. We recommend including 0.1 % sodium azide as a preservative if applicable. When reconstituted in 200 µl, the concentration of each individual single-domain antibody is 1.25 µM
kDa: -
Ext Coef: -
Shipping: Ambient temperature
Storing: Vials containing lyophilized protein can be stored at 4 °C for 6 months. We recommend reconstituting the protein with 50 % sterile glycerol including 0.1 % sodium azide as preservative if applicable. Minimize the number of freeze-thaw cycles by aliquoting the reconstituted protein. Long term storage at -80 °C for up to 6 months. Working aliquots can be stored at -20 °C for up to 4 weeks. We do not recommend storing the reconstituted protein at 4 °C.

This Product is not recommended to be used to detect proteins in Western Blott, sdAbs tend to recognize mainly native/folded proteins.

Look at detailed protocols and our specificity chart in our Resource Section.



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Notice: To be used in vitro/ for research only. Non-toxic, non-hazardous, non-infectious.
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