Alginates spheres in conservation bath, colored with bromothymol blue pH indicator.
A solution of calcium chloride with magnetic stirring.
Alginates spheres containing bromothymol blue pH indicator, mixed with a magnetic stirrer.
Drop a solution of sodium alginate (with bromothymol blue pH indicator) into a calcium chloride bath.
Drop a solution of sodium alginate (with phenolphthalein pH indicator) into a calcium chloride bath.
Turning of two alginate drops colored with bromothymol blue pH indicator from pH = 10 to pH = 4 (right) and 3 (left).
Turning of an alginate drop colored with phenolphthalein pH indicator from pH = 10 to pH = 2.