Quantification of Pt bound to DNA using total-reflection X-ray fluorescence (TXRF)

Abstract

Total-reflection X-ray fluorescence (TXRF), has been applied to a study of DNA platination kinetics of calf thymus in vitro, investigating the intercalation sequences of three Pt-containing medicines (cis-diamminedichloroplatinum(II) (cis-DDP), Pt-Berenil, and K₂PtCl₄) in DNA. The in vivo study was focused on the introduction process of the cis-DDP and the Pt-Berenil in HeLa cells. To quantify the amount of Pt bound to the DNA, TXRF needs a sample volume ≤100 µl. Pt concentrations from 3 to 30 ng ml^–1 were determined with a relative standard deviation between 2 and 8%. TXRF is shown as an alternative analytical technique for studying metal traces in a biochemical process.