摘要:
Gel holders for electrophoresis gels are made using clad fibers, particularly glass fibers as spacers between substrates. A plurality of fibers with a high-melting interior core and a low-melting external cladding are placed between a first planar substrate and a second planar substrate. The fibers are heated to a temperature sufficient to at least soften the exterior cladding of the fibers without softening the interior core of the fibers, and then cooled while they are in contact with the first and second substrates to solidify the exterior cladding. This adheres the fibers to the first and second substrates, and forms a gel chamber between said first and second substrates. The gel chamber has a thickness defined by interior core of the fibers. The fibers may be heated before or after the second substrate is placed over the top of the fibers. The gel holders thus formed may be filled immediately with a gel forming solution such as a polyacrylamide, or they may be stored indefinitely and used as needed.
摘要:
An apparatus and method for thermally cycling a reaction mixture in a reaction vessel to expose the mixture to the varying temperatures necessary to, for example, achieve PCR amplification or the preparation of sequencing fragments using a cycle sequencing operation makes use of flow-through reaction vessels, such as capillary tubes, for the preparation and thermal cycling of reaction mixtures. In order to prevent loss of the reaction mixture from the vessels during heating, the thermal cycling apparatus of the invention provides means for sealing the proximal and distal end of each reaction vessel. The proximal ends can be sealed by coupling to a pump which permits movement of the samples within the reaction vessels. As to the distal ends, the reaction vessels can be sealed by pressing the distal end of each vessel against a sealing element with a conformable surface, or by immersing the distal end of each vessel in the reservoir of liquid, preferably of an oil, that is not miscible with the reaction mixture.
摘要:
A high dynamic range apparatus for separation and detection of polynucleotide fragments has a housing adapted to receive an electrophoresis gel holder containing an electrophoresis gel loaded with fluorophore-labeled samples; one or more laser diodes for providing radiation of a frequency suitable for excitation of the fluorophore which irradiates a an array of excitation/detection sites on the electrophoresis gel; an array of detectors aligned with the excitation/detection sites for collecting fluorescent emissions; and one or more components for increasing the dynamic range of the instrument by at least an order of magnitude. These components, which can be used individually or in combination include detectors that are connected to a signal processing system that modulates the period of signal integration employed so that large signals are totaled at short time intervals and smaller signals are totaled at longer time intervals; the use of a beam splitter to produces a high intensity beam of emitted light and a low intensity beam of emitted light from each excitation/detection site; and a device for modulating the intensity of the excitation beam can be used to improve the dynamic range of the instrument.
摘要:
Gel holders for electrophoresis gels are made using clad fibers, particularly glass fibers as spacers between substrates. A plurality of fibers with an high-melting interior core and a low-melting external cladding are placed between a first planar substrate and a second planar substrate. The fibers are heated to a temperature sufficient to at least soften the exterior cladding of the fibers without softening the interior core of the fibers, and then cooled while they are in contact with the first and second substrates to resolidify the exterior cladding. This adheres the fibers to the first and second substrates, and forms a gel chamber between said first and second substrates. The gel chamber has a thickness defined by interior core of the fibers. The fibers may be heated before or after the second substrate is placed over the top of the fibers. The gel holders thus formed may be filled immediately with a gel forming solution such as a polyacrylamide, or they may be stored indefinitely and used as needed.
摘要:
Separation matrices useful in the formation of solid-state mm- to cm-scale devices for the rapid, high-resolution separation of single-stranded DNA ladder bands generated by the Sanger dideoxy- or Maxam/Gilbert chemical DNA sequencing procedures are formed from a solid support (1) having a plurality of posts (4) disposed on a first major surface thereof to form an obstacle course of posts (4) and pores (5). The posts are arranged in a regular X, Y array and are separated one from another by a distance of 100 nm or less, preferably 10 to 30 nm, and are optionally separated into lanes 2. The separation matrix can be manufactured by first forming a mold, preferably a reusable mold using lithography techniques. The mold is the reverse of the desired pattern of posts and pores of the obstacle course, and is used for casting the obstacle course. The cast obstacle course is then fused to a solid support and separated from the mold. Alternatively, the separation matrix can be formed from a polymer which undergoes specific and quantifiable swelling in the presence of a selected chemical compound. In this case, the matrix is cast on a mold in a conventional manner with a spacing between posts greater than the desired final spacing of 100 nm or less. For use, a buffer solution saturated with the specific chemical agent that controls swelling is added, causing the posts to swell to a defined amount to achieve the desired separation.
摘要:
A microelectrophoresis chip comprises a substrate in which there are formed one or more channels, one channel for each sample to be evaluated. The channels extend for the length of the chip, a distance of generally around 1 cm, and are about 1 to 10 &mgr;m wide and 1 to 10 &mgr;m in depth. The channels are filled with a homogeneous separation matrix which acts as an obstacle to the electrophoretic migration of the charged molecules. Microelectrodes disposed in the channels are used to induce an electric field within the homogeneous separation medium. When a voltage is applied across two or more of the microelectrodes, the charged molecules are induced to move and separate according to the electric field density, the type of solvent film, and the charge, shape and size of the charged molecule. The chip may further comprise detectors, such as light polarization detectors, fluorescence emission detectors, biosensors, electrochemical sensors or other microcomponents which may include sites for enzymatic or chemical manipulation of the moved or separated charged molecules.
摘要:
A microelectrophoresis chip comprises a substrate in which there are formed one or more channels, one channel for each sample to be evaluated. The channels extend for the length of the chip, a distance of generally around 1 cm, and are about 1 to 10 &mgr;m wide and 1 to 10 &mgr;m in depth. The channels are filled with a homogeneous separation matrix which acts as an obstacle to the electrophoretic migration of the charged molecules. Microelectrodes disposed in the channels are used to induce an electric filed within the homogeneous separation medium. When a voltage is applied across two or more of the microelectrodes, the charged molecules are induced to move and separate according to the electric field density, the type of solvent film, and the charge, shape and size of the charged molecule. The chip may further comprise detectors, such as light polarization detectors, fluorescence emission detectors, biosensors, electrochemical sensors or other microcomponents which may include sites for enzymatic or chemical manipulation of the moved or separated charged molecules.
摘要:
An electrophoresis microgel is formed in a gel holder. The gel holder comprises a top substrate, a bottom substrate and a spacer disposed between the top substrate and the bottom substrate. The spacer establishes a separation of from 25 to 250 microns between the top substrate and the bottom substrate. A gel compartment is formed by partially sealing the top substrate to the bottom substrate, while leaving an opening for the introduction of unpolymerized gel. The gel compartment is then filled with an unpolymerized gel, which is polymerized in the gel compartment. Electrodes may be printed on the substrates, may be contacts to an exposed edge of gel, or may be applied through windows cut into one of the substrates. One type of gel holder makes use of graded beads having a diameter of 25 to 250 microns slurried in an adhesive such as an acrylate adhesive as the spacer. The slurry is printed onto the surface of one or both substrates to form a spacer of the desired shape, and then hardened using heat or light. If desired, the spacer can establish lanes within the gel.
摘要:
Passive tags use two antennas with only limited mutual coupling, one of which receives a power/clock field and the other of which receives a data signal. An area-reading antenna, or two or more antennas, are deployed to generate the power/clock field, from a base station. The base station, or active tags, or both, generate the data signals from time to time. This topology together with the use of low frequencies permits area reads, and permits small and economical passive tags, and further permits localization of a particular passive tag as being nearby to a particular active tag.
摘要:
An alternative for smart card financial transactions is provided in which the smart card functionality is provided as part of a watch containing a RuBee antenna and transceiver for transmitting the authorization information to a receiver separate from the watch. This form factor allows the user to maintain the card in a readily usable and convenient location. In addition, the watch can be used to allow the user to specifically authorize or override a financial transaction, and to view and/or store information about the financial transaction, as well as conventional functionality such as alarms, and calendars. The watch of the invention can also provide access control or identification in corporate environments if desired.