We reported on a spectrophotometric determination of DNA binding protein, histone, with 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone and manganese(II) in a previous paper. In the present work, preconcentration method for the determination of histone, which involves the filtration of a histone - 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone - manganese(II) aggregate on a membrane filter, followed by its redissolution or tristimulus colorimetry, is described. Each of these methods is about 10-times more sensitive than the usual spectrophotometry.
