Abstract: Devices for detecting a particle in a fluid sample are provided. The device includes a segmented microfluidic conduit configured to carry a flow of a fluid sample, where the conduit includes one or more nodes and two or more sections, and a node is positioned between adjacent sections of the conduit. The device also includes a detector configured to detect a change in current through the conduit. Also provided are methods of using the devices as well as systems and kits that include the devices. The devices, systems and methods find use in a variety of different applications, including diagnostic assays.

Abstract: The present invention (also identified as “Capacitance cytometry”) relates to microfluidic and nanofluidic devices for detecting or measuring an electrical property of a fluid (liquid or aerosol), a single molecule, particle, or cell in fluid. In a particular embodiment, the devices detect or measure changes in capacitance of a fluid, molecule, particle or cell as it passes through the device. The invention relates to detection and measurement of single molecules, particularly biological molecules, and to methods of sequencing polynucleotide molecules (RNA or DNA) by detecting differentially labeled single nucleotides. Single molecule detection applications include DNA or RNA sequencing, detection of SNPs, protoemics, and particle sizing. The device can be used to determine cell DNA content, to analyze cell-cycle kinetics of cell populations, and to assay for abnormal changes in cell DNA content.

Abstract: A method for removing metal surface contaminants from silicon metalloid. The method comprises sequentially contacting the silicon with gaseous hydrogen fluoride and then with an aqueous solution comprising at least one-half weight percent hydrogen peroxide. The method is especially useful as a means for recovering metal surface contaminants on semiconductor grade silicon for analysis of surface contamination of the silicon by such metals. The method is useful for recovering copper from the surface of semiconductor grade silicon in an aqueous solution which can be analyzed directly to determine the amount of copper contamination of the surface of the silicon.