Streptavidin-Xtra™ IF488

Streptavidin conjugates are widely used in combing with biotin conjugates for detecting a variety of biological targets such as proteins, nucleic acids and other molecules. They are used as an ideal choice for many biological detections such as immunofluorescence microscopy, flow cytometry, western blot and other biological applications since streptavidin has a strong affinity binding biotin which is not affected over a broad range of pH and temperature. AAT Bioquest® offers a variety of streptavidin conjugates labeled with the classic fluorescent dyes (for example: FITC, TRITC, Texas Red®, Cy3®, Cy5® and Cy7®) and also our superior water soluble, photostable iFluor® and mFluor™ dyes. However, the conventional biotin-avidin detection systems are still limited by the limited signal intensity of the existing fluorescent conjugates. The Streptavidin Xtra™ iFluor conjugates are a new family of super bright streptavidin conjugates with nearly identical excitation and emission properties to Alexa Fluor fluorophores with 3~5 folds signal improvement. It is a set of powerful tools to detect low abundance targets in cell imaging or flow cytometry. iFluor® 488 is one of the most common green fluorescence colors for the FITC channel imaging.

Example protocol

PREPARATION OF STOCK SOLUTIONS

Unless otherwise noted, all unused stock solutions should be divided into single-use aliquots and stored at -20 °C after preparation. Avoid repeated freeze-thaw cycles

Streptavidin-Xtra™ IF488 stock solution (1 mg/mL)

Add 100 µL (For Cat# 46000) or 1 mL (For Cat# 46001) of ddH2O to the vial to make a 1 mg/mL stock solution.

Note: This constituted stock solution will be in PBS with 0.2% BSA.

PREPARATION OF WORKING SOLUTION

Streptavidin-Xtra™ working solution

For IF, the suggested staining concentration is 1-5 ug/ml. For FACS, the suggested concentration is at 0.1-0.5 ug / 100 uL / million cells in the staining buffer.

Note: PBS + 0.1% BSA can be used as a staining buffer.

Note: For the best performance of each application, the optimal concentration of this reagent needs to be carefully determined.

Note: The suggested working dilution is provided as a guide only. It is recommended that the users titrate the product in their tests using proper positive and negative controls.

SAMPLE EXPERIMENTAL PROTOCOL

Block and treat the samples with antibodies of interest as per the manufacturer's recommendations.
Add biotin-conjugated secondary antibody working solution in the samples at appropriate concentration and duration.

Note: Please verify the compatibility and type of your biotin-conjugated antibody with the primary antibody used in the experiment. For example, If the primary antibody is a mouse antibody, then a goat anti-mouse antibody bound with biotin can be used for the assay.
Incubate the cells with Streptavidin-Xtra™ working solution at room temperature for 30 minutes to 1 hour. Note: Optimal time for incubation needs to be determined carefully.
Remove the working solution and resuspend the cells in your choice of buffer.
Take the image using the fluorescence microscope or record the intensity using flow cytometer.

Spectrum

Open in Advanced Spectrum Viewer

Product family

Name	Excitation (nm)	Emission (nm)	Extinction coefficient (cm ^-1 M ^-1)	Quantum yield	Correction Factor (260 nm)	Correction Factor (280 nm)
Streptavidin-Xtra™ IF555	557	570	100000¹	0.64¹	0.23	0.14
Streptavidin-Xtra™ IF594	568	587	100000¹	0.57¹	0.34	0.15
Streptavidin-Xtra™ IF647	656	670	250000¹	0.25¹	0.03	0.03

Citations

View all 36 citations: Citation Explorer

Highly sensitive electrochemical biosensor for streptavidin detection based on CdSe quantum dots
Authors: Wei, Y. P., Liu, X. P., Mao, C. J., Niu, H. L., Song, J. M., Jin, B. K.
Journal: Biosens Bioelectron (2018): 99-103

Efficient streptavidin-functionalized nitrogen-doped graphene for the development of highly sensitive electrochemical immunosensor
Authors: Yang, Z., Lan, Q., Li, J., Wu, J., Tang, Y., Hu, X.
Journal: Biosens Bioelectron (2017): 312-318

High-sensitive surface plasmon resonance microRNA biosensor based on streptavidin functionalized gold nanorods-assisted signal amplification
Authors: Hao, K., He, Y., Lu, H., Pu, S., Zhang, Y., Dong, H., Zhang, X.
Journal: Anal Chim Acta (2017): 114-120

Correction to Peptide Tag-Induced Horseradish Peroxidase-Mediated Preparation of a Streptavidin-Immobilized Redox-Sensitive Hydrogel
Authors: Mishina, M., Minamihata, K., Moriyama, K., Nagamune, T.
Journal: Biomacromolecules (2017): 311

Sensitive detection of platelet-specific antibodies with a modified MAIPA using biotinylated antibodies and streptavidin-coated beads
Authors: Mortberg, A., Meinke, S., Berg, P., Killie, M. K., Kjeldsen-Kragh, J., Jaras, K., Refsum, E., Hoglund, P., Wikman, A.
Journal: J Immunol Methods (2016): 9-15

Page updated on December 17, 2024

Ordering information

Price
Unit size	100 ug 1 mg
Catalog Number	4600046001
Quantity

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Additional ordering information

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Spectral properties

Correction Factor (260 nm)	0.21
Correction Factor (280 nm)	0.11
Extinction coefficient (cm ^-1 M ^-1)	75000¹
Excitation (nm)	491
Emission (nm)	516
Quantum yield	0.9¹