Indo-1
Encyclopedia
Indo-1 is a popular calcium indicator similar to Fura-2
. In contrast to Fura-2, Indo-1 has a dual emissions peak. The main emission peak in calcium-free solution is 475 nm while in the presence of calcium
the emission is shifted to 400 nm. It is widely used in flow cytometry
.
The penta potassium salt is commercially available and preferred to the free acid because of its higher solubility in water. While Indo-1 is not cell permeable the penta acetoxymethyl ester Indo-1 AM enters the cell where it is cleaved by intracellular esterases to Indo-1.
The synthesis and properties of Indo-1 were presented in 1985 by the group of Roger Y Tsien
.
Fura-2
Fura-2, a polyamino carboxylic acid, is a ratiometric fluorescent dye which binds to free intracellular calcium. It was the first widely-used dye for calcium imaging, and remains very popular. Fura-2 is excited at 340 nm and 380 nm of light, and the ratio of the emissions at those...
. In contrast to Fura-2, Indo-1 has a dual emissions peak. The main emission peak in calcium-free solution is 475 nm while in the presence of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
the emission is shifted to 400 nm. It is widely used in flow cytometry
Flow cytometry
Flow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...
.
The penta potassium salt is commercially available and preferred to the free acid because of its higher solubility in water. While Indo-1 is not cell permeable the penta acetoxymethyl ester Indo-1 AM enters the cell where it is cleaved by intracellular esterases to Indo-1.
The synthesis and properties of Indo-1 were presented in 1985 by the group of Roger Y Tsien
Roger Y. Tsien
Roger Yonchien Tsien is a Chinese American biochemist and a professor at the Department of Chemistry and Biochemistry, University of California, San Diego...
.