SPECTROPHOTOMETRIC MICROMETHOD FOR PROTEIN DETERMINATION WITH TETRACHLORO TETRAIODO FLUORESCEIN

Reaction of tetrachloro tetraiodo nuorescein (Na2TCTIF) with protein r esults in an increase in its absorption at 568nm. This assay gives a l inear response to BSA at 0.68-34.0 mu g/ml, and is almost as sensitive as the Bradford method(1). The reaction is completed in approximately 2 min and has good color stability for at least 1 h. Addition of trit on X-100 increases the sensitivity and stability of Na2TCTIF binary sy stem and the reason was studied. The binary and ternary assays were co mpared in protein-to-protein variability, interferences and the type o f binding effort. In detection of human serum albumin, these two ways give results with good reproducibility and are comparable with the bro mocresol green (BCG) method.