Fluo-2 Low Affinity (LowAff)

  • #0240 TEFLabs Fluo-2 LowAff(AM) 1mg... $130 Add to Cart
  • #0242 TEFLabs Fluo-2 LowAff(AM) 20 x 50 ug... $150 Add to Cart
  • #0244 TEFLabs Fluo-2 LowAff(salt) 1 mg... $130 Add to Cart
  • #0246 TEFLabs Fluo-2 LowAff(AM) 2 x 50 ug... $20 Add to Cart
  • #0248 TEFLabs Fluo-2 LowAff(salt) 2 x 25 ug... $20 Add to Cart

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Fluo-2 is one of the original Fluo series of Ca2+ indicators invented by Roger Tsien in the 1980s. Whereas Fluo-3 and Fluo-4 were commercialized, Fluo-2 was not. Subsequently, Fluo-2 has been found to be much brighter (1.5x) than Fluo-4 in cellular experiments. The increased brightness of Fluo-2 is partly attributable to its superior loading in most cell types.

Low affinity (lowAff, formerly designated as “FF”) versions enable studies where a large concentration of calcium is expected. They have two major advantages over their high affinity counterparts. They cause reduced buffering of intracellular calcium and reduced perturbation of calcium transients, and they allow for measurements of shorter-lived transients.


Excitation:  488 nm

Emission:  515 nm

kd: 6.7 µM

Solubility: H20 (salt form)  DMSO (AM form)

Molecular Weight: 913 g/mol (salt)  1083 g/mol (AM)

Typical loading protocol for Fluo-2. (The protocol for using Fluo-2 is the same that is used for Fluo-4)
  • Prepare stock solution of 1 – 10 mM Fluo-2 (AM) in DMSO
  • Dilute AM stock solution to 1 – 5 μM in aqueous medium and incubate cells for 30 – 60 minutes at room temperature. (If necessary, premix Pluronic F-127 stock solution (15% wt/vol in DMSO) with the desired volume of Fluo-2 (AM) stock solution before dispersal into aqueous medium.)
  • Wash/transfer cells into fresh medium for experimentation (for “wash-free” assays, washing may be omitted).




Fluo-2 HighAff


Fluo-2 LeakRes

Fluo-2 NearMem

Fluo-2 NearMem

Asante Calcium Red Low Affinity

Asante Calcium Green Low Affinity