ABSTRACT
Theophylline is a potent bronchodilator with a narrow therapeutic index. A simple fluorescent biosensor that detects clinically relevant theophylline concentrations has been developed using the well-characterized theophylline binding RNA aptamer. Hybridization of the RNA aptamer to a fluorescently labeled DNA strand (FL-DNA) yields a fluorescent RNA:DNA hybrid that is sensitive to theophylline. The biosensor retains the remarkable selectivity of the RNA aptamer for theophylline over caffeine and is sensitive to 0-2 muM theophylline, well below the clinically relevant concentration (5-20 mg/L or approximately 10-50 muM). Adding a dabcyl quenching dye to the 3'-terminus of the fluorescently labeled DNA strand yielded a dual-labeled DNA strand (FL-DNA-Q) and increased the dynamic range of this simple biosensor from 1.5-fold to 4-fold.
Subject(s)
Aptamers, Nucleotide/chemistry , Biosensing Techniques , Fluorescent Dyes/pharmacology , RNA/chemistry , Theophylline/chemistry , Aptamers, Nucleotide/chemical synthesis , Caffeine/chemistry , DNA/chemistry , Dose-Response Relationship, Drug , Models, Chemical , Nucleic Acid Conformation , Nucleic Acid Hybridization , Spectrometry, Fluorescence , TemperatureABSTRACT
Health care providers in rural settings are faced with the same issues as those in urban areas, write Susan Dymond, M.B.A., and Christopher Rankin, but those issues are compounded by the isolation of distance. One answer to this problem is to use telecommunications and satellite technology to bridge these distances and that's just what Texas Tech University is doing.
