Quantitative Analysis of Fluorescent Dye-labeled DNA by High Resolution Inductively Coupled Plasma Mass Spectrometry

An accurate mass determination method for fluorescent dye-labeled DNA by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS) was established.This method allow for the mass of fluorescent dye-labeled DNA to be traceable to the International system of units.The fluorescent dye-labeled DNA was processed by co-lumn chromatography,ultracentrifugation and dialysis.The purity was detected by electrophoresis chip and electrical conductivity.The fluorescent dye-labeled DNA was digested with microwave in nitric acid.The phosphorus from the fluorescent dye-labeled DNA was quantitatively determined by HR-ICP-MS.The parameters of HR-ICP-MS and microwave digestion were optimized.The interference factors of HR-ICP-MS such as physical interference,signal drift interference,isotopes and phosphorus element speciation interference were analyzed and corrected with ultra-filtration,internal standard of Y(88.906),certified reference material of phosphate,nucleotide and oligo DNA.The uncertainty in measurement was evaluated mainly from method precision,phosphorus certified reference material(CRM),nitric acid digestion,mass of sample and CRM.The uncertainty(≤8.4%) was smaller than ultraviolet spectrophotometry,fluorescence spectrophotometry and real time PCR.This method will aide in the development of certified reference materials(CRMs) with certified nucleic acid(DNA,RNA) content.