Fluo-4FF, AM, cell permeant - Special Packaging (Invitrogen™)

Labeled calcium indicators are molecules that exhibit an increase in fluorescence upon binding Ca²⁺. Fluo-5F, fluo-5N, and fluo-4ff are analogs of fluo-4 with lower Ca²⁺-binding affinity, making them suitable for detecting intracellular calcium levels in the 1 μM to 1 mM range that would saturate the response of fluo-3 and fluo-4. Cells may be loaded with the AM ester forms of these calcium indicators by adding the dissolved indicator directly to dishes containing cultured cells. These indicators are compatible with excitation at 488 nm by argon-ion laser sources, making them useful for confocal microscopy, flow cytometry, and microplate screening applications.

Learn more about ion indicators including calcium, potassium, pH, and membrane potential indicators ›

Calcium Indicator (AM Ester) Specifications:
• Label (Ex/Em of Ca²⁺–bound form): Fluo-4ff (494/516 nm)
• Fluorescence intensity increase upon binding Ca²⁺: >100 fold
• K_d for Ca²⁺ in buffer: ∼9.7 μM
• Exhibit fluorescence increase upon binding Ca²⁺ with little shift in wavelength

Using TPEN to Control Heavy Metal Cations
In addition, BAPTA-based indicators such as these bind various heavy metal cations (e.g., Mn²⁺, Zn²⁺, Pb²⁺) with substantially higher affinity than Ca²⁺. Perturbations to calcium measurements caused by presence of these ions can be controlled using the heavy metal-selective chelator TPEN.

More Choices for Fluorescent Calcium Indicators
We offer a large selection of Molecular Probes™ calcium indicators for use in various experimental scenarios. For more information, review Fluorescent Ca²⁺ Indicators Excited with Visible Light—Section 19.3 in the Molecular Probes™ Handbook.

For UV-excitable Ca²⁺ indicators, protein-based Ca²⁺ indicators, conjugates of Ca²⁺ indicators, and for fluorescence-based indicators of other metal ions (i.e., Mg²⁺, Zn²⁺) review Indicators for Ca²⁺, Mg²⁺, Zn²⁺ and Other Metal Ions—Chapter 19 in the Molecular Probes™ Handbook.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.