© 2005 Oxford University Press
Luminescence anisotropy-based detection of nucleic acids and proteins using long-lifetime Ru(II) complex as a luminescent label
1 Department of Polymer Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan, 2 Department of Biomedical Engineering, Advanced Medical Engineering Center, Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
Luminescence anisotropy-based methods are powerful tool for the detection of biomolecules in homogeneous physiological media without Bound/Free separation. However, analyses based on the method are always disturbed by the autofluorescence from biological specimen. This disturbance limits the sensitivity of the method. To improve the detection limit of the method, a long-lifetime luminophore was adopted as the label. Because of the lifetime of the autofluorescence is below 10ns, it is expected that the use of the long-lifetime luminophore enables us to avoid the disturbance by adopting time-resolved luminescence anisotropy measurement. To verify this concept, oligodeoxyribonucleotides and Staphylococcus aureus protein A were labeled with Ru(II) complex (
500nsec) and used for the detection of Escherichia coli 16S ribosomal RNA (16S rRNA) and immunoglobulin G (IgG), respectively. Results indicated that the methods were useful for the detection of rRNA and IgG without disturbance of the autofluorescence.