Biomedical subjects

Maria C Carles

Publications and source records attributed to Maria C Carles.

3 recordsLinked to original sources

PubMed2006

Polymerase chain reaction on microchips.

The polymerase chain reaction (PCR) provides an in vitro method for rapid enzymatic amplification of fragments of DNA. Microchip-based PCR devices (with reaction volumes from picoliters to microliters) have been realized using various combinations of silicon, glass, and/or plastic materials. Passivation of exposed surfaces in the microreactor is critical for successful PCR. Silicon and plastic surfaces can be passivated by silanization. With surface passivation, PCR can be performed efficiently and economically in chip-based microreactors. The reduced thermal mass of microchips allows for extremely fast temperature ramping. PCR protocols established for benchtop reactors may need to be adjusted accordingly when transferred to microchips. Here, we provide detailed protocols for microchip PCR including procedures for surface passivation and bonding of glass to silicon with ultraviolet curable glue, because both procedures have a major influence on the success or failure of the PCR.

Electrophoresis, Microchip↗

PubMed2003

Microfabricated PCR-electrochemical device for simultaneous DNA amplification and detection.

Microfabricated silicon/glass-based devices with functionalities of simultaneous polymerase chain reaction (PCR) target amplification and sequence-specific electrochemical (EC) detection have been successfully developed. The microchip-based device has a reaction chamber (volume of 8 microl) formed in a silicon substrate sealed by bonding to a glass substrate. Electrode materials such as gold and indium tin oxide (ITO) were patterned on the glass substrate and served as EC detection platforms where DNA probes were immobilized. Platinum temperature sensors and heaters were patterned on top of the silicon substrate for real-time, precise and rapid thermal cycling of the reaction chamber as well as for efficient target amplification by PCR. DNA analyses in the integrated PCR-EC microchip start with the asymmetric PCR amplification to produce single-stranded target amplicons, followed by immediate sequence-specific recognition of the PCR product as they hybridize to the probe-modified electrode. Two electrochemistry-based detection techniques including metal complex intercalators and nanogold particles are employed in the microdevice to achieve a sensitive detection of target DNA analytes. With the integrated PCR-EC microdevice, the detection of trace amounts of target DNA (as few as several hundred copies) is demonstrated. The ability to perform DNA amplification and EC sequence-specific product detection simultaneously in a single reaction chamber is a great leap towards the realization of a truly portable and integrated DNA analysis system.

Electrochemistry↗

PubMed2002

Genotyping on a complementary metal oxide semiconductor silicon polymerase chain reaction chip with integrated DNA microarray.

A novel method for the fast identification of genetic material utilizing a micro-DNA amplification and analysis device (micro-DAAD) consisting of multiple PCR microreactors with integrated DNA microarrays was developed. The device was fabricated in Si-technology and used for the genotyping of Chinese medicinal plants on the basis of differences in the noncoding region of the 5S-rRNA gene. Successful amplification of the genetic material and the consecutive analysis of the fluorescent-labeled amplicons in the micro-DAAD by the integrated oligonucleotide probes were demonstrated. Parallel analysis was performed by loading the four PCR reactors of the micro-DAAD with different samples of 3-microL volume. Temperature sensors and heating elements of the micro-DAAD enable precise temperature control and fast cycling, allowing the rapid completion of a combined amplification and analysis (hybridization) experiment.

Genotype↗