F D & C #3
FD & C Red No. 3
FDC Red No. 3
Spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-, disodium salt
A tetraiodofluorescein used as a red coloring in some foods (cherries, fish), as a disclosure of DENTAL PLAQUE, and as a stain of some cell types. It has structural similarity to THYROXINE.