Molecular Probes™ Streptavidin, Alexa Fluor™ 555 Conjugate

Alexa Fluor™ 555 streptavidin comprises a biotin-binding protein (streptavidin) covalently attached to a fluorescent label (Alexa Fluor™ dye).

Product Code	Brand	Form	Quantity
10453442	Molecular Probes™ S21381	Solid	1 mg
10728853	Molecular Probes™ S32355	Liquid	0.5 mL

Description

Alexa Fluor™ 555 streptavidin comprises a biotin-binding protein (streptavidin) covalently attached to a fluorescent label (Alexa Fluor™ dye). Streptavidin has a very high binding affinity for biotin, and a conjugate of streptavidin is commonly used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids, and other molecules (for example, a biotinylated primary antibody bound to a protein target can be detected with a fluorescently labeled streptavidin). Strategies similar to this are used in many detection protocols including western blots, flow cytometry, imaging and microscopy, and microplate assays. Alexa Fluor™ dye streptavidin conjugates are supplied as 1 mg lyophilized product or in 0.5 mL volumes of a 2 mg/mL solution.

Important Features of Alexa Fluor™ 555 Streptavidin Conjugates:
• Alexa Fluor™ 555 streptavidin conjugate has Ex/Em maxima of ∼ (555/565)
• Bright, photostable fluorescence
• High solubility in aqueous solutions
• Available in multiple colors
• Ideal for western blots, flow cytometry, imaging and microscopy, microplate assays and more

Properties of Alexa Fluor™ Dyes
Alexa Fluor™ dyes are organic fluorescent dyes developed for better performance in imaging and other labeling protocols and exhibit improved photostability and brightness and improved solubility in aqueous solutions. Available in a broad range of colors, these dyes are a good choice for most imaging applications.

Blocking Endogenous Biotin
Naturally occurring biotins can interfere with biotin-streptavidin detection schemes. For experiments involving fixed and permeabilized cells, try our Endogenous Biotin-Blocking Kit (Cat. No. E21390) to minimize this interference.

For Research Use Only. Not intended for any animal or human therapeutic or diagnostic use.

See User Manual for solubility instructions.

Specifications

• Conjugate: Alexa Fluor 555
• Product Line: Alexa Fluor™
• Product Type: Streptavidin Conjugate (fluorescent)

For Research Use Only. Not for use in diagnostic procedures.