Influenes of non-selective interactions of nucleic acids on response rates of nucleic acid fiber optic biosensors

摘要

The immobilization of oligonucleotides to solid surfaces can provide a platfonn of chemistry that is suit- able for the development of biosensor and m.icroarray technologies. Experiments were performed using a fiber optic nucleic acid biosensor based on total internal reflec- tion fluorescence to examine the effects of the presence of non-complementary DNA on the detection of hybridiza- tion of complementary target DNA. The work has focused on the rates and extent of hybridization in the presence and absence of non-selective adsorption using fiuores- cein-labeled DNA. A stop-flow system of 137 ~Lvolume pennitted rapid introduction and mixing of each sample. Response times measured were on the order of seconds to minutes. Non-selective adsorption of non-complementary oligonucleotides (ncDNA) was found to occur at a signif- icantly faster rate than hybridization of complementary oligomers (cDNA) in all cases. The presence of ncDNA oligonucleotides did not inhibit selective interactions be- tween immobilized DNA and cDNA in solution. The pres- ence of high concentrations of non-complementary ge- nomic DNA had little effect on the extent of hybridiza- tion of complementary oligonucleotides, but actually re- duced the response times of sensors to cDNA oligonu- cleotides.