Bicarbonate Ion → 2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid

Participants

Reaction Steps

VM-2 antibody (5 mg/ml) was reacted with a tenfold molar excess of fluorescein isothiocyanate immobilized on Celite (Molecular Probes) for 30 minutes in the dark at room temperature in a 0.2M bicarbonate buffer, pH 9.2. Excess fluorescein isothiocyanate was removed by gel chromatography on a Sephadex G50 column in phosphate buffered saline. The fluorophore/protein ratio was calculated from the absorbance of the conjugate at 493 nm and 280 nm and varied between 2.4 to 4.2 from one preparation to another.

Provenance & Evidence