| abstract |
Diether symmetrically substituted fluoresceins are provided having at least one anionic group and a linking functionality. Depending upon the site of substitution, the compounds can be used as fluorescers absorbing at wavelengths in excess of 500 nm or as quenchers, absorbing at wavelengths in excess of 500 nm and exhibiting substantially no fluorescence. The compounds find wide application, particularly as labels in fluorescent immunoassays. |