Alexa Fluor Fluorescent Streptavidin and Avidin Conjugates

showcase.par.67122.image.180.120.1.s002437-photostability-gif

We offer a broad range of Alexa Fluor fluorescent streptavidin conjugates (Table 1 and Table 3) and avidin conjugates (Table 2). These dyes represent a major breakthrough in the development of fluorescent labeling reagents and, without exception, produce the best and brightest conjugates we have ever tested. Benefits of the Alexa Fluor dyes and their conjugates include exceptionally bright conjugates, excellent photostability, and a broad range of emission colors. These characteristics make Alexa Fluor dyes the best choice for most imaging applications.

View all Alexa Fluor Fluorescent Streptavidin Conjugates

Table 1. Alexa Fluor Fluorescent Streptavidin Conjugates

Streptavidin Conjugates	Ex (nm)*	Em (nm)*	Cat . No.
Alexa Fluor 350 Streptavidin	346	442	S11249 (1 mg)
Alexa Fluor 405 Streptavidin	402	421	S32351 (1 mg)
Alexa Fluor 430 Streptavidin	434	539	S11237 (1 mg)
Alexa Fluor 488 Streptavidin	495	519	S11223 (1 mg) S32354 (0.5 mL)
Alexa Fluor 500 Streptavidin	503	525	S32352 (1 mg)
Alexa Fluor 514 Streptavidin	518	540	S32353 (1 mg)
Alexa Fluor 532 Streptavidin	530	554	S11224 (1 mg)
Alexa Fluor 555 Streptavidin	555	565	S21381 (1 mg) S32355 (0.5 mL)
Alexa Fluor 546 Streptavidin	556	573	S11225 (1 mg)
Alexa Fluor 568 Streptavidin	578	603	S11226 (1 mg)
Alexa Fluor 594 Streptavidin	590	617	S11227 (1 mg) S32356 (0.5 mL)
Alexa Fluor 610 Streptavidin	612	628	S32359 (1 mg)
Alexa Fluor 633 Streptavidin	632	647	S21375 (1 mg)
Alexa Fluor 635 Streptavidin	633	647	S32364 (1 mg)
Alexa Fluor 647 Streptavidin	650	668	S21374 (1 mg) S32357 (0.5 mL)
Alexa Fluor 660 Streptavidin	663	690	S21377 (1 mg)
Alexa Fluor 680 Streptavidin	679	702	S21378 (1 mg) S32358 (0.5 mL)
Alexa Fluor 700 Streptavidin	702	723	S21383 (1 mg)
Alexa Fluor 750 Streptavidin	749	775	S21384 (1 mg)

*Approximate fluorescence excitation (Ex) an d emission (Em) maxima for conjugates, in nm.

Alexa Fluor Streptavidin Fluorescent Conjugates in Action

Multicolor fluorescence microscopy analysis of muntjac fibroblasts. The actin cytoskeleton was labeled with biotin phalloidin and visualized using Alexa Fluor 350 streptavidin. Mitochondria were stained with MitoTracker Red CMXRos; the nucleus was labeled with an anti-phosphohistone primary antibody and visualized using Alexa Fluor 500 goat anti–mouse IgG.

The cytoskeleton of a fixed and permeabilized bovine pulmonary artery endothelial cell. Tubulin was detected using mouse monoclonal anti–α-tubulin antibody and visualized with Alexa Fluor 647 goat anti–mouse IgG antibody (pseudocolored magenta). Endogenous biotin in mitochondria was labeled with green-fluorescent Alexa Fluor 488 streptavidin; DNA was stained with blue-fluorescent DAPI.

Table 2. Alexa Fluor® NeutrAvidin and Avidin Conjugates

Fluorescent Conjugate	Ex (nm)*	Em (nm)*	Cat . No.
Alexa Fluor 350 Neutravidin	346	442	A11236
Alexa Fluor 488 Avidin	495	519	A21370

*Approximate fluorescence excitation (Ex) an d emission (Em) maxima for conjugates, in nm.<

Alexa Fluor–Phycobiliprotein Streptavidin Conjugates

We offer fluorescent streptavidin conjugates of with tandem dyes R-PE (R-Phycoerythrin) and APC (Allophycocyanin) labeled with long-wavelength Alexa Fluor dyes. Our tandem conjugates (Table 3) comprise a donor phycobiliprotein—R-PE or APC—conjugated to longer wavelength–emitting fluorescence acceptors. By the process of fluorescence resonance energy transfer (FRET), an energy transfer cascade is established wherein most of the light absorbed by the donor R-PE or APC results in fluorescence of the acceptor dye. This process can be quite efficient, resulting in almost total transfer of energy to the acceptor dye.

Table 3. Tandem Alexa Fluor–Phycobiliprotein Streptavidin Conjugates

R-PE, B-PE, and Tandem–R-PE Conjugates
Streptavidin Conjugates	Ex (nm)*	Em (nm)*	Cat . No.
Alexa Fluor 610–R-PE Streptavidin	496, 546, 565 †	630	S20982
Alexa Fluor 647–R-PE Streptavidin	496, 546, 565 †	668	S20992
Alexa Fluor 680–R-PE Streptavidin	496, 546, 565 †	702	S20985
Alexa Fluor 750–R-PE Streptavidin	496, 546, 565 †	771	S32363

APC and Tandem-APC Conjugates
Streptavidin Conjugates	Ex (nm)*	Em (nm)*	Cat . No.
Allophycocyanin (APC) Streptavidin	650	660	S868, S32362 ‡
Alexa Fluor 680–APC Streptavidin	650	702	S21002
Alexa Fluor 700–APC Streptavidin	650	723	S21005
Alexa Fluor 750–APC Streptavidin	650	775	S21008

*Approximate fluorescence excitation (Ex) an d emission (Em) maxima for conjugates, in nm

Resources