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J Khandurina

Publications and source records attributed to J Khandurina.

5 recordsLinked to original sources
PubMed2000

Integrated system for rapid PCR-based DNA analysis in microfluidic devices.

An integrated system for rapid PCR-based analysis on a microchip has been demonstrated. The system couples a compact thermal cycling assembly based on dual Peltier thermoelectric elements with a microchip gel electrophoresis platform. This configuration allows fast (approximately 1 min/ cycle) and efficient DNA amplification on-chip followed by electrophoretic sizing and detection on the same chip. An on-chip DNA concentration technique has been incorporated into the system to further reduce analysis time by decreasing the number of thermal cycles required. The concentration injection scheme enables detection of PCR products after performing as few as 10 thermal cycles, with a total analysis time of less than 20 min. The starting template copy number was less than 15 per injection volume.

DNA↗
PubMed1999

Microfabricated porous membrane structure for sample concentration and electrophoretic analysis.

A microfabricated injection valve incorporating a porous membrane structure is reported that enables electrokinetic concentration of DNA samples using homogeneous buffer conditions followed by injection into a channel for electrophoretic analysis. The porous membrane was incorporated in the microchannel manifold by having two channels separated from each other by 3-12 microns and connected by a thin porous silicate layer. This design allows the passage of current to establish an electrical connection between the separated channels but prevents large molecules, e.g., DNA, from traversing the membrane. Concentrated DNA can be injected into the separation channel and electrophoretically analyzed. Experiments exhibit a nonlinear increase in concentration with time, and DNA fragments can be concentrated up to 2 orders of magnitude as shown by comparison of peak intensities for analysis performed with and without concentration.

DNA↗
PubMed1998

Multiple sample PCR amplification and electrophoretic analysis on a microchip.

Polymerase chain reactions (PCRs) were carried out on as many as four DNA samples at a time on a microchip device. The PCR products were then analyzed, either individually or together on the same device, by microchip gel electrophoresis. A standard PCR protocol was used to amplify 199- and 500-base pair (bp) regions of bacteriophage lambda DNA and 346- and 410-bp regions of E. coli genomic and plasmid DNAs, respectively. Thermal lysis of the bacteria was integrated into the PCR cycle. A product sizing medium, poly(dimethylacrylamide), and an intercalating dye for fluorescence detection were used in the electrophoretic analysis of the products. PCR product sizes were determined by coelectrophoresis with marker DNA.

DNA, Bacterial↗
PubMed1998

Microchip device for cell lysis, multiplex PCR amplification, and electrophoretic sizing.

The steps of cell lysis, multiplex PCR amplification, and electrophoretic analysis are executed sequentially on a monolithic microchip device. The entire microchip is thermally cycled to lyse cells and to amplify DNA, and the products are then analyzed using a sieving medium for size separation and an intercalating dye for fluorescence detection. Using a standard PCR protocol, a 500-base pair (bp) region of bacteriophage lambda DNA and 154-, 264-, 346-, 410-, and 550-bp regions of E. coli genomic and plasmid DNAs are amplified. The electrophoretic analysis of the products is executed in <3 min following amplification using hydroxyethyl cellulose or poly(dimethylacrylamide) sieving gels. Product sizing is demonstrated by proportioning the amplified product with a DNA sizing ladder.

DNA, Bacterial↗