Asante Calcium Red-2 (ACR-2) known commercially as ICR (Ionbiosciences Calcium Red)

One of the great achievements of the late Roger Tsien, a 2008 Nobel Prize winner in chemistry, was the invention or creation of a compound that allows scientists to study calcium in the cell, in the cytosol, non-invasively through fluorescence. These compounds, which I call modern fluorescence calcium indicators are now used in research and in drug screening and mostly use UV or green fluorescence. There has been an effort to make red emitting calcium indicators since the first one was reported in 1985 without success.
This book accounts for the study of calcium in the cell before Roger Tsien's creation of the first fluorescent calcium indicator in the 1970s, and the development of the modern fluorescent calcium indicators from 1982 to the present time. The book also gives an account of red emitting calcium indicators from the beginning, 1985 to 2014 as reported by Martin Oheim in a review article where he decries the absence of any useful red emitting calcium indicators, and the development of the first true cytosolic red emitting calcium indicator, ICR, by the author including the design, synthesis, properties, and an unedited application from four scientists. The absence of a patent allows any scientist to make it for their research or screening needs. It is a legacy product from the author who started it all with Roger and has retired after forty years.