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J Ferrance

Publications and source records attributed to J Ferrance.

3 recordsLinked to original sources

Polymerase chain reaction in polymeric microchips: DNA amplification in less than 240 seconds.

There is much interest in developing methods amenable to amplifying nucleic acids by the polymerase chain reaction (PCR) in small volumes in microfabricated devices. The use of infrared-mediated temperature control to accurately thermocycle microliter volumes in microchips fabricated from polyimide is demonstrated. Amplification of a 500-base-pair fragment of lambda-phage DNA was achieved in a 1.7-microl chamber containing a thermocouple that allowed for accurate control of temperature. While previous work showed that Taq polymerase was inactivated when in direct contact with the thermocouple, this was circumvented with the polyimide chip by the addition of polyethylene glycol as a buffer additive. This, consequently, allowed for adequate amounts of PCR product to be observed after only 15 cycles, with a total time for amplification of 240 s.

Bacteriophage lambda↗

Miniaturized electrophoresis: an evolving role in laboratory medicine.

The promise of capillary electrophoresis (CE) for supplanting conventional methods in the clinical laboratory led to intense interest in this analytical tool a decade ago. Since then, a number of clinical applications have been defined along with those that have impacted the pharmaceutical, environmental, and forensic arenas. Concurrent with the development of CE applications was the emergence of electrophoresis in the microchip format. The main attraction of this platform, the ability to execute high-resolution separations in a few hundred seconds, was not its only attribute. The capability for parallel processing of separations was complemented by the potentialfor integrating sample preparation into the same device. This Review highlights recent progress towards CE and microchip electrophoresis as clinical diagnostic tools, with literature coverage from 1996 to 2000.

Blood Proteins↗

Exploiting sensitive laser-induced fluorescence detection on electrophoretic microchips for executing rapid clinical diagnostics.

Fluorescence is used as a sensitive detection technique for current clinical diagnostics procedures involving slab gel separations of DNA. In transferring electrophoretic separations to smaller formats, first capillaries and then microchips, the size of the sample being separated has decreased considerably, making it necessary to routinely detect a few hundred molecules of each component in the sample. Laser-induced fluorescence detectors provide high sensitivity and can be employed in both direct and indirect modes to detect clinically relevant compounds. A number of examples show that there is no loss of clinical diagnostic capability in moving these analyses to microchip devices. Microchips also allow for parallel processing of samples by incorporating multiple channels in a single device, with a number of strategies possible for using LIF detection in these multiplex systems.

DNA↗