Abstract: A test strip device exhibits visual changes, such as color changes, when there is a only slight difference in the composition of liquids such as gasoline, oil, ethanol and water. Such a slight liquid composition difference usually requires a sophisticated and expensive instrument to differentiate. The test strip consists of one and more than one inverse opal films deposited on a substrate and achieves this goal of differentiation in a simple, fast and energy-free manner.

Abstract: Nucleic acid hybridization methods are disclosed. An example method comprises: immobilizing probe nucleic acid molecules on a surface; flowing target nucleic acid molecules to the immobilized probe nucleic acid molecules on said surface in a hybridization buffer solution; washing said surface with a wash solution which comprises nanoparticles; and detecting the presence of duplexes on said surface comprising a strand of one of said target nucleic acid molecules and a strand of one of said probe nucleic acid molecules. In some embodiments, the target nucleic acid molecules are generated using a helicase-dependent amplification method wherein the reaction solution comprises nanoparticles.

Abstract: Particles, such as cells, are isolated for conducting single-particle measurement. Isolation of rare cells, such as circulating tumor cells (CTCs), from blood is technically challenging because they are small in numbers. An integrated microfluidic biochip, dubbed as CTC chip, was designed and fabricated for conducting tumor cell isolation. As CTCs are usually multidrug resistance (MDR), the effect of MDR inhibitors on chemotherapeutic drug accumulation in the isolated single tumor cell is measured. In this invention, label-free isolation of the rare tumor cells was conducted based on cell size difference. The major advantages of the CTC chip are the ability of fast cell isolation, followed by multiple rounds of single-cell measurement, suggesting a potential assay for detecting the drug responses based on the liquid biopsy of cancer patients.

Abstract: The invention encompasses microfluidic microarray assemblies (MMA) and subassemblies and methods for their manufacture and use. In one embodiment, first and second channel plates are provided and are sealingly connected to a test chip in consecutive steps. Each plate includes microfluidic channels configured in a predetermined reagent distribution pattern. The test chip comprises a plurality of discrete test positions, each test position being located at the intersection between a first predetermined reagent pattern and a second predetermined reagent pattern, wherein at least one of said patterns is non-linear. The first channel plate allows the distribution of a first reagent on said test chip, wherein said first reagent is immobilized at said test positions. The second channel plate allows the distribution of a second reagent on said test chip, wherein said second reagent comprises a plurality of different test samples.

Abstract: The invention provides nucleic acid hybridization methods for detecting target nucleic acid sequences wherein complexes comprising nanoparticles non-covalently associated with single-stranded tartlet nucleic acid molecules are incubated with immobilized probe nucleic acid molecules. Because the nanoparticles function as competitors in the hybridization reaction between the target nucleic acid molecules and the probe nucleic acid molecules. The methods provide a high degree of discrimination between a perfectly matched target sequence and a sequence having at least a single-base-pair mismatch, even when the hybridization reaction is performed at room temperature. The invention also provides microarray methods and apparatus which incorporate the nanoparticle-assisted hybridization methods.

Abstract: The invention relates to a microfluidic device. The microfluidic device comprises a fluid chamber comprising a particle retention region for retaining at least one particle, such as a cell. The microfluidic device also comprises a plurality of electrodes extending into the particle retention region for applying a dielectrophoretic (DEP) force to controllably move the particle within the particle retention region. The invention also relates to methods of using the microfluidic device to controllably move the particle within the microfluidic device and to monitor, observe, or measure a parameter of the particle. The particle movement may be caused by a DEP force and/or a fluidic force.

Abstract: The invention relates to a microfluidic device comprising one or more fluid channels, one or more fluid ports, and a V-shaped particle retention structure. The fluid channel is generally opposite the particle retention structure, fluid ports are located between the fluid channel and the particle retention structure, and the particle retention structure has sloped side walls. Fluid, including reagents, can be delivered to the microfluidic device through the one or more fluid channels or the fluid ports. The invention also relates to methods of using the microfluidic device to monitor, observe, measure, or record a biological parameter of a particle, to separate a single particle from a group of particles, to culture a cell, to treat a particle, and to move a particle back and forth in the device.

Abstract: A microfluidic chip for carrying out live cell assays and showing observable color change is provided. The microfluidic chip has at least one fluid channel and a plurality of holes punched in a first side of the chip in fluid communication with the at least one fluid channel. Gelled medium containing live cells may be applied to the holes without obstructing the at least one fluid channel. A plain disk is applied to a second side of the chip to seal the fluid channels. Liquid to be distributed to the cells in the holes may be flowed through the at least one fluid channel by spinning the chip. The gelled medium may alternatively contain a reagent to be assayed by producing an observable change upon interaction with a second reagent when the chip is spun.

Abstract: Microarray devices fabricated using microfluidic reagent distribution techniques are provided. As described herein, the invention encompasses microfluidic microarray assemblies (MMA) and subassemblies and methods for their manufacture and use. In one embodiment first and second channel plates are provided which may be sealed to a test chip in consecutive steps. Each channel plate includes microfluidic channels configured in a predetermined reagent distribution pattern. For example, the first channel plate may have a radial (linear) reagent distribution pattern and the second channel plate may have a spiral (curved) reagent distribution pattern, or vice versa. In one embodiment the first channel plate is connected to the test chip and at least one first reagent is distributed on the test chip in a first predetermined reagent pattern. The first reagent is then immobilized on the test chip.

Abstract: The invention relates to a microfluidic device comprising one or more fluid channels, one or more fluid ports, and a V-shaped particle retention structure. The fluid channel is generally opposite the particle retention structure, fluid ports are located between the fluid channel and the particle retention structure, and the particle retention structure has sloped side walls. Fluid, including reagents, can be delivered to the microfluidic device through the one or more fluid channels or the fluid ports. The invention also relates to methods of using the microfluidic device to monitor, observe, measure, or record a biological parameter of a particle, to separate a single particle from a group of particles, to culture a cell, to treat a particle, and to move a particle back and forth in the device.