Abstract: Provided are a centrifugal force based microfluidic device which can automatically perform a dilution operation and a microfluidic system including the same. The centrifugal force based microfluidic device for dilution includes a rotatable disk type platform, a mixing chamber disposed on the platform; a buffer solution storage disposed on a portion of the platform which is closer to a center of the platform than the mixing chamber, connected to the mixing chamber through a channel to supply a predetermined amount of buffer solution to the mixing chamber at least one time, and a plurality of diluted solution chambers which are disposed on a portion of the platform which is farther from the center of the platform than the mixing chamber, are each connected to the mixing chamber through flow paths extended from a middle exit corresponding to a predetermined water level, and sequentially receiving a solution which is serially diluted in the mixing chamber at least one time.

Abstract: A method of reducing a temperature difference between a high-temperature and a low-temperature substrate includes interposing a heat transfer facilitating layer which has a higher thermal conductivity than air and can hold particles between the substrates, and maintaining close contact between the high-temperature substrate, the heat transfer facilitating layer, and the low-temperature substrate, wherein formation of an air layer can be at least substantially prevented between the high-temperature substrate and the heat transfer facilitating layer, and between the low-temperature substrate and the heat transfer facilitating layer. A fluid reaction device includes a microfluidic reaction chip which accommodates a fluid, a heater, and a heat transfer facilitating layer which is interposed between the microfluidic reaction chip and the heater, the heat transfer facilitating layer has a higher thermal conductivity than air and can hold particles, wherein formation of an air layer can be prevented.

Abstract: A method of reducing a temperature difference between a high-temperature and a low-temperature substrate includes interposing a heat transfer facilitating layer which has a higher thermal conductivity than air and can hold particles between the substrates, and maintaining close contact between the high-temperature substrate, the heat transfer facilitating layer, and the low-temperature substrate, wherein formation of an air layer can be at least substantially prevented between the high-temperature substrate and the heat transfer facilitating layer, and between the low-temperature substrate and the heat transfer facilitating layer.

Abstract: A method of controlling a mobile terminal, and which includes displaying, on a touch screen display of the mobile terminal, an operation screen corresponding to a current operating mode executing on the mobile terminal; detecting, via a detecting device, a touch input on the touch screen display of the mobile terminal; determining, via a controller on the mobile terminal, a first finger characteristic describing a finger touching the touch screen display and a second finger characteristic describing the finger touching the touch screen display that is different than the first finger characteristic; performing, via the controller, a first operation relevant to the current operating mode based on the determined first finger characteristic; and performing, via the controller, a second operation relevant to the current operating mode based on the determined second finger characteristic.

Abstract: A method of sequentially performing concentration and amplification of nucleic acid in a single micro chamber includes: introducing a nucleic acid-containing sample and a solution including a kosmotropic salt to a micro chamber having a hydrophilic interior surface to concentrate the nucleic acid by binding the nucleic acid on the interior surface of the micro chamber; and performing a polymerase chain reaction (PCR) by adding a PCR mixture to the chamber. Since the nucleic acid is reversibly bound to the interior surface of the micro chamber, PCR yield is higher compared with a surface of aluminum oxide in which irreversible binding occurs. In addition, all processes are sequentially performed in a single micro chamber so that the number of samples, consumables, time, and labor for treatment and analysis can be reduced, detection sensitivity can be improved, and risk of sample cross contamination significantly reduced without sample loss by eliminating transporting of the sample.

Abstract: A micro-fluid reaction vessel includes an upper plate formed of an elastomer, a lower plate adhered to the upper plate, a micro-chamber and a micro-channel formed on an inner surface of the upper plate facing the lower plate and an inlet hole and an outlet hole formed in the upper plate and through which a fluid flows into or out of, respectively. The micro-channel is constructed to be closed by pressure applied to the upper plate and elastically restored when the pressure is not applied. A micro fluid reaction method uses the micro fluid reaction vessel and a method of manufacturing forms the microfluid reaction vessel.

Abstract: Provided is a method for quantifying an initial concentration of a nucleic acid from a real-time nucleic acid amplification data. Nucleic acid (DNA or RNA) extracted from organism or virus is amplified using an enzyme. Then, the initial concentration of the nucleic acid is found by calculating the characteristic amplification cycle number or the characteristic amplification time at which the fluorescence intensity of the nucleic acid subtracted by the background fluorescence intensity of the nucleic acid has half of its maximum value, or the characteristic amplification cycle number or the characteristic amplification time at which the amplification efficiency has the maximum or the minimum value, or the prior-to-amplification fluorescence intensity of the nucleic acid subtracted by the background fluorescence intensity of the nucleic acid. Accordingly, the initial concentration of the nucleic acid can be calculated without differentiation or integration.

Abstract: Provided is a microfluidic device for electrochemically regulating the pH of a fluid. The microfluidic device includes: an ion-exchange material; an anode chamber having a surface defined by a surface of the ion-exchange material and an anode electrode disposed along an edge of the surface of the anode chamber; and a cathode chamber having a surface defined by a surface of the ion-exchange material and a cathode electrode disposed along an edge of the surface of the cathode chamber, wherein the anode chamber and the cathode chamber are separated by an insulation material.

Abstract: An apparatus for regulating salt concentration, a lab-on-a-chip including the same and a method of regulating salt concentration using the apparatus are provided. The apparatus includes: a reaction chamber that is defined by a cation exchange membrane and an anion exchange membrane and is selected from the group consisting of a biomolecule extraction chamber, an amplification chamber, a hybridization chamber, and a detection chamber; a first electrode chamber that is defined by the anion exchange membrane and a first electrode and includes an ion exchange medium; and a second electrode chamber that is defined by the cation exchange membrane and a second electrode and includes an ion exchange medium. Even without injecting solutions with different salt concentrations into the reaction chamber by operating pumps and valves for each operation stage, the salt concentration can be reversibly regulated in situ by adjusting the polarity, intensity and application time of a voltage.

Abstract: Provided is a method for quantifying an initial concentration of a nucleic acid from a real-time nucleic acid amplification data. Nucleic acid (DNA or RNA) extracted from organism or virus is amplified using an enzyme. Then, the initial concentration of the nucleic acid is found by calculating the characteristic amplification cycle number or the characteristic amplification time at which the fluorescence intensity of the nucleic acid subtracted by the background fluorescence intensity of the nucleic acid has half of its maximum value, or the characteristic amplification cycle number or the characteristic amplification time at which the amplification efficiency has the maximum or the minimum value, or the prior-to-amplification fluorescence intensity of the nucleic acid subtracted by the background fluorescence intensity of the nucleic acid. Accordingly, the initial concentration of the nucleic acid can be calculated without differentiation or integration.

Abstract: A handheld centrifuge includes an inertia body having an axle and a pair of inertia wheels coupled to the axle. The inertia wheels are coupled to the axle in substantially perpendicular direction to the axle, and spaced apart from each other. A string is connected to the axle. At least one closed vessel is detachably installed on an outer face of the inertia wheel to contain a substance to be centrifuged. The closed vessel is installed in substantially radial direction of the inertia wheel.

Abstract: Provided is a method of isolating and purifying biomolecules using a hydrogel, the method including: bring a sample containing charged biomolecules into contact with a hydrogel to bind the biomolecules to the hydrogel; washing the hydrogel bound with the biomolecules; and eluting the bound biomolecules using an elution solvent. According to the method, the use of a hydrogel with a large surface area reduces the isolation time of biomolecules to 5 min or less, an external device such as an electromagnet is not required, and small-sized systems or LOC can be easily implemented due to applicability to microsystems through a polymer patterning technique.

Abstract: Provided are a microfluidic device that performs a biochemical reaction using a small amount of a biochemical fluid and detects the result thereof, and a method of fabricating the same. The microfluidic device includes: a substrate which comprises a chamber that is formed as a concave groove and accommodates a fluid in the bottom surface of the substrate, and is formed of polymer; and a film welded on the bottom surface of the substrate to seal the chamber so that the chamber is not open at the bottom surface of the substrate, and formed of polymer. The method of fabricating a microfluidic device includes: preparing a substrate which comprises a chamber that is formed as a concave groove and accommodates a fluid in the bottom surface of the substrate, and is formed of polymer; and welding a film on a bottom surface of the substrate to seal the chamber so that the chamber is not opened at the bottom surface of the substrate, the film being formed of polymer.

Abstract: Disclosed is a method of determining an initial concentration of a target nucleic acid within a sample using real-time nucleic acid amplification data. Amplification efficiencies of the target nucleic acid with respect to amplification time are obtained from signals of amplified products, and an amplification efficiency function with respect to amplification time is formulated employing the amplification efficiencies.

Abstract: The present invention provides a method of selectively lysing non-viable cells from a cell population within a sample, the method including selectively lysing non-viable cells by mixing a cell-containing sample with a lysis buffer including a non-ionic surfactant and a divalent cation salt.

Abstract: Provided is a cell lysis method including: preparing a cell sample to be lysed; heating the cell sample; and cooling the cell sample by causing an endothermic reaction near the cell sample. According to the method, cell lysis can be simply and conveniently performed without regard to location and without additional devices since a separate energy source is not required and the apparatus is portable. In particular, when cell lysis is performed in a biochip using a small amount of sample, a greater cell lysis effect can be obtained. In addition, cell lysis efficiency is significantly improved, compared to when only heating is performed.

Abstract: Provided is kit for and a method of amplifying a nucleic acid using rolling cyclic amplification (RCA), including amplifying a nucleic acid together with formation of a single-strand circular DNA template using RCA by reacting a reaction solution including: (a) two hairpin oligos, (b) a target nucleic acid, (c) a DNA ligase,(d) an endonuclease, (e) a DNA polymerase, and (f) a primer.

Abstract: Provided is a method of lysing a cell or a virus using a free radical. The method includes: applying an electric field to a mixture of a metal ion, a peroxide, and a cell or virus solution to increase the free radical generation, thereby lysing a cell or a virus. In the present method, cell lysis may be efficiently performed using a low electrical energy (several mV to several V). When the present method is applied to a microsystem, cell lysis can occur at a desired time and in a desired space by controlling the electrical energy, thus being suitable to realize a lab-on-a-chip (LOC).

Abstract: Provided is a microfluidic device including a substrate; a chamber formed by a groove in a bottom surface of the substrate, whereby a fluid can be accommodated in the chamber; and an adhesive tape adhered to the bottom surface of the substrate, wherein the adhesive tape includes a polymer film and a silicone adhesive agent coated on the polymer film.

Abstract: Provided is a method of treating a surface of a substrate used in a biochemical reaction system, the method including forming a polymer film on the surface by vapor deposition of a compound of formula (1) below and a compound of formula (2) below: (RO)3—Si—(CH2)n1—X??(1) (RO)3—Si—(CH2)n2—(CF2)m—X??(2) wherein R is one of a methyl group and an ethyl group, X is one of a methyl group and a trifluoromethyl group, n1 is an integer from 1 to 3, n2 is an integer from 1 to 10, and m is an integer from 1 to 10.