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 and Alexa Fluor Plus phalloidin conjugates

Phalloidin Conjugates For Staining Actin 

We provide a number of Invitrogen 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

Fluorescent Alexa Fluor and Alexa Fluor Plus dye conjugates of phalloidin are widely used F-actin stains, with color choices across the full spectral range. These phalloidin conjugates provide researchers with fluorescent probes that are designed to be superior in brightness and photostability to all other spectrally similar conjugates tested. Alexa Fluor Plus Phalloidin conjugates are specially designed to have maximum density of phalloidin and dye molecule, on F-actin filament, resulting in 3-5 times more signal sensitivity and brightness. This extra brightness is especially useful when conducting challenging F-actin imaging, such as with SIM, or STORM, or when reliable staining is needed of stress fibers.

Staines Nuclei and F-actin

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

Spectral characteristics of Invitrogen phalloidin probes