Phalloidin conjugates

Phalloidin is a toxin isolated from the deadly Amanita phalloides mushroom. It is a bicyclic peptide that binds specifically to F-actin. Fluorescent conjugates of phalloidin are convenient tools to investigate the distribution of F-actin in fixed and permeabilised cells or tissue sections. One unit (U) of phallodin is sufficient to stain one sample (200 µl staining volume). A highly selective actin filament stain for fixed and permeabilised cells. Labeled phalloidins have similar affinity for both large and small filaments.

• Choice of 18 bright and photostable CF® dyes, biotin, or other common fluorophores
• Dye options for super-resolution and 2-photon imaging
• Excellent signal to background with negligible non-specific staining

Biotium offers a variety of phalloidin products, including conjugates of our outstanding CF™ dyes, which offer advantages in brightness, photostability, and/or signal-to-noise ratio compared to other fluorescent dyes. Please see the CF™ dye reference chart under the datasheets tab to select the appropriate CF™ dye for your application.

CF™ is a trademark of Biotium, Inc. Texas Red® is a registered trademark of Molecular Probes, Inc. It is a bicyclic peptide that binds specifically to F-actin. Fluorescent conjugates of phalloidin are convenient tools to investigate the distribution of F-actin in fixed and permeabilized cells or tissue sections. One unit (U) of phallodin is sufficient to stain one sample (200 µl staining volume).

Fluorescently-labeled phalloidins bind to F-actin with nanomolar affinity. Labeled phalloidins have similar affinity for both large and small filaments, binding in a stoichiometric ratio of about one phalloidin molecule per actin subunit in muscle and nonmuscle cells from various species of plants, animals and fungi. Different from antibodies, the binding affinity of phalloidin does not change significantly with actin among different species.

Fluorescently-labeled phalloidin is typically used to stain fixed and permeabilised cells. Labeled phalloidins are not cell-permeant and have therefore has not been used extensively with living cells, however they can be loaded into live cells via cationic liposomes.

Biotium's next-generation CF® dyes were designed to be highly water-soluble with advantages in brightness and photostability compared to Alexa Fluor®, DyLight®, and other fluorescent dyes.

Ordering information: Supplied as lyophilised solid in 50 U and 300 U sizes. Typical staining concentration for F-actin in fixed and permeabilised cells is 5 U/ml.

Packaging: Phalloidin stock solutions are very stable. But binding of fluorescent phalloidins to cells is more labile than other probes, such as antibodies, and staining can become non-specific or lost over time. For best results, store phalloidin-stained samples in a suitable mounting medium at 4 °C, protected from light. For certain phalloidin conjugates, especially CF®405M, CF®555, CF®647, and CF®680, Biotium recommends imaging immediately or shortly after staining. Staining with Biotium's other CF® dye phalloidins usually is stable for up to a week when specimens are stored at 4 °C, protected from light.