Terbium as a fluorescent probe for DNA and chromatin
Abstract
Terbium reacted with DNA and chromatin to form a complex in which terbium acted as a sensitive fluorescent probe. By measuring the narrow-line emission of Tb-3+ when DNA is selectively excited, the relative amount of Tb-3+ bound to the DNA can be calculated. Terbium was bound to DNA until one Tb-3+ was present for each phosphate group. After this point no more terbium was bound. TbCl3 was bound to chromatin in a linear manner until approximately 0.48 TbCl3 was added for each phosphate group in the chromatin-DNA solution. From these data it appears that 52% of the phosphate groups in chromatin were unavailable for binding. The binding of Tb-3+ to DNA can be reversed by prolonged dialysis against 0.5 M NaCl and chelating agents. The terbium ion is ideal in that it binds DNA tight enough so that completion of the reaction can be assumed but loose enough so that it can be removed by gentle means. Low concentrations of salt (up to 2 mM NaCl) enhance the quantum efficiency. Below pH 3 and above pH 7 the DNA-terbium complex will not form. Between pH 3 and pH 7 the quantum efficiency of the DNA terbium complex increases from either pH to a maximum at pH 5.5 to 5.6. Several biochemical uses for Tb-3+ ion are suggested.
Read the paper
Related studies
- Quantum dots: synthesis, bioapplications, and toxicity
- A Guide to In Silico Drug Design
- Quantum Computing for Healthcare: A Review
- Automated in Silico Design of Homogeneous Catalysts
- Identification of Novel 3-Hydroxy-pyran-4-One Derivatives as Potent HIV-1 Integrase Inhibitors Using in silico Structure-Based Combinatorial Library Design Approach
- In silico structural elucidation of RNA-dependent RNA polymerase towards the identification of potential Crimean-Congo Hemorrhagic Fever Virus inhibitors
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.