ABSTRACT
A general multipurpose microchip technology platform for point-of-care diagnostics has been developed. Real-time nucleic acid sequence-based amplification (NASBA) for detection of artificial human papilloma virus (HPV) 16 sequences and SiHa cell line samples was successfully performed in cyclic olefin copolymer (COC) microchips, incorporating supply channels and parallel reaction channels. Samples were distributed into 10 parallel reaction channels, and signals were simultaneously detected in 80 nl volumes. With a custom-made optical detection unit, the system reached a sensitivity limit of 10(-6) microM for artificial HPV 16 sequences, and 20 cells microl(-1) for the SiHa cell line. This is comparable to the detection limit of conventional readers, and clinical testing of biological samples in polymer microchips using NASBA is therefore possible.
Subject(s)
Biomarkers, Tumor/analysis , Microfluidic Analytical Techniques , Nanotechnology/methods , Polymers/chemistry , RNA, Viral/analysis , Uterine Cervical Neoplasms/virology , Cell Line, Tumor , Female , Humans , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Self-Sustained Sequence Replication/methods , Sensitivity and SpecificityABSTRACT
Real-time nucleic acid sequence-based amplification (NASBA) is an isothermal method specifically designed for amplification of RNA. Fluorescent molecular beacon probes enable real-time monitoring of the amplification process. Successful identification, utilizing the real-time NASBA technology, was performed on a microchip with oligonucleotides at a concentration of 1.0 and 0.1 microM, in 10- and 50-nL reaction chambers, respectively. The microchip was developed in a silicon-glass structure. An instrument providing thermal control and an optical detection system was built for amplification readout. Experimental results demonstrate distinct amplification processes. Miniaturized real-time NASBA in microchips makes high-throughput diagnostics of bacteria, viruses, and cancer markers possible, at reduced cost and without contamination.
