Support & Resources



A fixable red fluorescent nerve terminal probe that is spectrally identical to SynaptoRed™ C2 (also called FM®4-64).

Product Attributes

Cellular localization


For live or fixed cells

For live/intact cells

Assay type/options

Real-time imaging

Fixation options

Fix after staining (formaldehyde), Permeabilize after staining




510/750 nm (see product description)

Note: Due to operating restrictions related to our COVID-19 response, primary antibody conjugates of R-PE, APC, PerCP, HRP, or AP are temporarily unavailable. All other antibody options are still available. We apologize for the inconvenience. Please see our easy-to-use Mix-n-Stain™ Antibody Labeling Kits for labeling antibodies with R-PE, APC, tandem dyes, and enzymes.
Catalog #
1 mg
Clear selection
Add to wishlist
(Please select quantity above )

Wishlist updated! View wishlist

Shipping, Handling & Tax (CA only) not included in price. Learn more

Tax is assessed in the state of California. All fees will be calculated during checkout based on your shipping information and are subject to change.

SPECIAL - Order 5 or more and receive 10% off.

Request a Bulk Quote

Product Description

AM4-66 is a fixable red fluorescent nerve terminal probe. The dye is spectrally identical to SynaptoRed™ C2 (also called FM®4-64), but it has an additional amine group at the hydrophilic end of the molecule, making the dye fixable with formaldehyde or gluteraldehyde. The long emission wavelength makes the dye suitable to be used with GFP in two-color imaging.

  • Red fluorescent nerve terminal probe that is fixable with formaldehyde or gluteraldehyde
  • λExEm (membranes) = ~510/750 nm*
  • Dark purple solid soluble in water
  • MW: 872.85

* Excitation/emission settings of 515/640 nm have been used for detection of yeast vacuole staining with SynaptoRed™ C2 (FM®4-64), and should be applicable to AM4-66.
FM is a registered trademark of Thermo Fisher Scientific.

You may also like…