Phalloidin Conjugates For Staining Actin  

We provide a number of Molecular Probes® fluorescent and biotinylated derivatives of phalloidin that deliver significant advantages over antibodies for actin labeling. The binding properties of phalloidin conjugates do not change appreciably with actin from different species, including plants and animals. In addition, they exhibit negligible nonspecific staining, so the contrast between stained and unstained areas is high.

See additional products for cytoskeleton staining

Phalloidin overview

Phalloidin is a bicyclic peptide that belongs to a family of toxins isolated from the deadly Amanita phalloides “death cap” mushroom and is commonly used in imaging applications to selectively label F-actin in fixed cells, permeabilized cells, and cell-free experiments. Labeled phalloidin conjugates have similar affinity for both large and small filaments and bind in a stoichiometric ratio of about one phallotoxin per actin subunit in both muscle and nonmuscle cells; they reportedly do not bind to monomeric G-actin, unlike some antibodies against actin.

Alexa Fluor® phalloidin conjugates

Fluorescent conjugates of phalloidin using the Molecular Probes® Alexa Fluor® dyes are widely used F-actin stains, with color choices across the full spectral range. Alexa Fluor® phalloidin conjugates provide researchers with fluorescent probes that are designed to be superior in brightness and photostability to all other spectrally similar conjugates tested.

Phalloidin, Alexa Fluor® Fluorescent Conjugates  
Fixed, permeabilized bovine pulmonary artery endothelial cells visualized using components of the SelectFX® Nuclear Labeling Kit and Alexa Fluor® phalloidin conjugates. Nuclei and F-actin were stained, respectively, with (top left) DAPI and Alexa Fluor® 680 phalloidin, (top right) SYTOX® Green dye and Alexa Fluor® 568 phalloidin, (bottom left) 7-AAD and Alexa Fluor® 488 phalloidin, and (bottom right) TO-PRO®-3 dye and Alexa Fluor® 350 phalloidin.

Spectral characteristics of Molecular Probes® phalloidin probes

Actin-selective probe Ex/Em* ~ MW Cat. No.
Alexa Fluor® 350 Phalloidin 346/442 † 1100 A22281
NBD phallacidin 465/536 1040 N354
Fluorescein phalloidin 496/516 † 1175 F432
Alexa Fluor® 488 Phalloidin 496/519 † 1180 A12379
Oregon Green® 488 phalloidin 496/520 † 1180 O7466
BODIPY® FL Phallacidin 505/512 1125 B607
Oregon Green® 514 phalloidin 511/528 † 1281 O7465
Rhodamine phalloidin 540/565 † 1250 R415
Alexa Fluor® 555 Phalloidin 555/565 † 1910 A34055
BODIPY® 558/568 phalloidin 558/569 1115 B3475
Alexa Fluor® 594 Phalloidin 590/617 † 1620 A12381
Texas Red®-X phalloidin 591/608 † 1490 T7471
BODIPY® 650/665 Phalloidin 647/661 1200 B12382
Alexa Fluor® 647 Phalloidin 650/665 † 1950 A22287
Alexa Fluor® 680 Phalloidin 679/702 † 1850 A22286
Biotin-XX Phalloidin NA 1300 B7474
* Excitation (Ex) and emission (Em) maxima, in nm. Spectra of phallotoxins are either in aqueous buffer, pH 7–9 (denoted †) or in methanol.
For Research Use Only. Not for use in diagnostic procedures.