Thermo Fisher, S21381, Streptavidin, Alexa Fluor™ 555 conjugate, 1 mg

Quantity: 1 mg
Form: Solid
Unit Size: Each
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 moreProperties of Alexa Fluor™ DyesAlexa 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 BiotinNaturally 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.