Abstract: In a mass spectrometer or gas chromatograph/mass spectrometer system, a conditioning gas such as, for example, hydrogen is added to condition or clean one or more components or regions of the mass spectrometer such as the ion source. The conditioning gas may be added upstream of the mass spectrometer such as, for example, into a sample inlet or a chromatographic column, or may be added directly into the mass spectrometer. The conditioning gas may be added off-line, when the mass spectrometer is not analyzing a sample, or on-line during sample analysis. When added on-line, the conditioning gas may be mixed with a carrier gas such as, for example, helium. In another embodiment, the conditioning gas also serves as the carrier gas through the column; another gas such as, for example, helium may be added to the carrier gas stream.

Abstract: A method of filtering a signal sampled by a sampler, for example, in an equivalent time oscilloscope includes applying a correction to an actual frequency response of the sampler, with respect to a reference frequency response, to a first frequency range of the sampled signal, and transitioning across a second frequency range of the sampled signal from the correction applied to the first frequency range to no correction of the actual frequency response of the sampler, the second frequency range being higher than the first frequency range. The method further includes compensating in a third frequency range of the sampled signal for excess gain incurred while applying the correction and transitioning from the correction to no correction in the first and second frequency ranges, respectively, so that statistics of asynchronous components of the sampled signal are preserved, the third frequency range being higher than the second frequency range.

Abstract: A drive mechanism for back pressure regulator used in liquid chromatography, supercritical fluid chromatography, or supercritical fluid extraction allows very fine automated control over a very wide range of pressures by combining a linear actuator compressing a spring, pushing a pin. The nozzle assembly of the regulator comprises a flow through chamber containing a diaphragm and a seat, in which the pin pushes the diaphragm against the seat, together with an upstream pressure sensor and electronic feedback control to the motor of the actuator. The BPR of the embodiments exhibits high pressure stability and extremely low pressure noise, even at moderate to high pressures. The exemplary BPR can be use at either constant pressure or to generate pressure programs where the pressure is varied versus time. Further, the nozzle assembly has a field-replaceable head, requiring no mechanical adjustment on replacement.

Abstract: A system and method for determining the performance of a channel emulator includes an input signal, at least one transmitter configured to receive the input signal, the at least one transmitter coupled to at least one receiver through the channel emulator, the at least one transmitter configured to transmit the input signal through the channel emulator, the at least one receiver configured to receive a faded receive signal. The system also comprises a signal processor configured to receive a processor signal and the faded receive signal, the signal processor configured to correlate the processor signal and the faded receive signal to develop a correlated signal that represents a channel impulse of the channel emulator. The channel impulse of the channel emulator is used to extract at least one channel coefficient that reflects the performance of the channel emulator.

Abstract: Provided are improved processes and apparatuses for solid phase oligonucleotide synthesis, the improvements comprising carrying out detritylation of the nascent oligonucleotide using a composition of an organic solvent, a protic solvent and a selected concentration, or selected concentration range, of water. In some embodiments, an oligonucleotide synthesis apparatus includes means for adding water to a detritylation reagent. In some embodiments, an apparatus can include a water detector for analyzing the water concentration of a detritylation reagent to be reacted with a nascent oligonucleotide. An apparatus can comprise a feedback loop to control the concentration of water at the point of the detritylation reaction and/or to control the detritylation reaction time. The apparatuses and methods reduce batch-to-batch variations in the manufacture of oligonucleotides immobilized on the surface of various substrates.

Abstract: Aspects of the invention provide systems and methods for high-throughput screening of fluidic samples. In some embodiments, two chromatography columns are utilized in series. The first chromatography column can have a high affinity for phosphorylated compounds while the second chromatography column has a high affinity for one or more analytes of interest.

Abstract: A system for performing analog-to-digital conversion comprises a sampling unit that generates multiple digital samples from an analog input signal at each recurrence of a periodic interval, and a processing unit that combines the digital samples to produce a digital output signal. In certain embodiments, the sampling unit comprises multiple analog-to-digital converters arranged in parallel, and the processing unit comprises a digital signal processor that detects outliers in the digital samples and averages any non-outliers among the digital samples to generate the digital output signal.

Abstract: A magnetic resonance imaging (MRI) apparatus comprises a plurality of cylindrical electromagnetic coils arranged in a coaxial configuration around a sample region. The coils are used to capture resonance signals from a sample at different times according to a geometric echo effect. The measurements can then be combined to produce an MRI signal.

Abstract: A current probe enabling measurement of current of a signal in a circuit includes a ferrite core defining a gap, a wire wrapped around the ferrite core and a magnetic field sensor. The wire is configured to receive the signal from the circuit, where the current of the signal flowing in the wire generates a magnetic field in the ferrite core. The magnetic field sensor is positioned in the gap of the ferrite core, the magnetic field generated in the ferrite core flowing through the magnetic field sensor, which produces a voltage proportional to an intensity of the magnetic field. The current is measured based on the voltage produced by the magnetic field sensor.

Abstract: Ionization devices that have at least two modes of ionization, and that can switch between these two modes of operation, are described. Illustratively, the ionization devices can switch between a photoionization (PI) mode and a combined mode of electroionization (EI) and PI (EI/PI mode).

Abstract: One embodiment of the invention provides a method of preparing an eluted sample containing salts or buffers from a liquid chromatography device for analysis by a mass spectrometry device. The method includes: continuously providing a non-polar solvent to the mass spectrometry device; receiving the eluted sample from the liquid chromatography device; flowing the eluted sample over a solid phase extraction column; flowing the non-polar solvent over the solid phase extraction column; and presenting non-polar solvent and the eluted sample to the mass spectrometry device.

Abstract: Responses of voltage and current probes are characterized or corrected. A voltage probe method includes measuring output of the voltage probe and a first output of a through, in response to an input signal applied to the through, with the voltage probe connected, measuring a second output of the through with the voltage probe disconnected, and characterizing the response of the voltage probe using the output of the voltage probe and the first and/or second outputs. A current probe method includes measuring output current of the current probe and first output current of a through, in response to an input signal applied to the through with the current probe connected in series, measuring second output current of the through with the current probe disconnected, and characterizing the response of the current probe using the output current of the current probe and the first and/or second output currents of the through.

Abstract: A DC-balanced signal is imposed on the input of a transmission line. Prior to imposing the DC-balanced signal, the input of the transmission line is held at an intermediate DC level that intermediate between the maximum and minimum DC levels of the DC-balanced signal. Alternatively, a compensating pulse is additionally imposed on the input of the transmission line. The compensating pulse compensates for a change in the DC level at the output of the transmission line caused by the imposing of the DC-balanced signal on the input of the transmission line.

Abstract: A power diverter has a first terminal for interposition between a signal input and a signal output. A MEMS switch is coupled to the first terminal and has a MEMS switch control input. A MEMS protection switch is coupled to the MEMS switch and has a protection switch control input. The switch control inputs are configured to receive control signals for selectively placing the power diverter in i) an ON state in which signal power at the signal input is diverted from the signal output via the MEMS switch and the MEMS protection switch, ii) an OFF state in which signal power at the signal input is not diverted from the signal output, and in which the MEMS switch mitigates an insertion loss and distortion imparted by the MEMS protection switch to a signal path between the signal input and the signal output, and iii) an intermediary state in which the MEMS protection switch reduces current flow through the MEMS switch.

Abstract: A switchable valve for a sample injector includes a first valve member and a second valve member that can moved with respect to the other. The first valve member includes a plurality of ports, the second valve member includes a plurality of fluid paths. The plurality of ports include eight circumferential ports distributed along a circumference and one central port arranged at a central position of the first valve member. The plurality of fluid paths include three arcuate fluid paths so as to be couplable with at least two of the circumferential ports and one straight fluid path extending between the central position and a circumferential position so as to be couplable with the central port and one of the circumferential ports.

Abstract: In a mass spectrometer or gas chromatograph/mass spectrometer system, a conditioning gas such as, for example, hydrogen is added to condition or clean one or more components or regions of the mass spectrometer such as the ion source. The conditioning gas may be added upstream of the mass spectrometer such as, for example, into a sample inlet or a chromatographic column, or may be added directly into the mass spectrometer. The conditioning gas may be added off-line, when the mass spectrometer is not analyzing a sample, or on-line during sample analysis. When added on-line, the conditioning gas may be mixed with a carrier gas such as, for example, helium. In another embodiment, the conditioning gas also serves as the carrier gas through the column; another gas such as, for example, helium may be added to the carrier gas stream.

Abstract: A frame for a microfluidic chip may be used together with a laboratory apparatus. The frame is adapted at least for one of the following features: receiving the microfluidic chip; protecting the microfluidic chip; and, positioning the microfluidic chip relative to the frame. The microfluidic chip is movable relative to the frame.

Abstract: A method of genome analysis is provided. In certain embodiments, the method comprises: a) contacting a double-stranded genomic DNA with a site-specific nicking endonuclease that recognizes a sequence comprising a single nucleotide polymorphism (SNP), in which the endonuclease nicks the genomic DNA at a nick site only if a first allele of the SNP is present; b) denaturing the genomic sample; c) contacting the denatured genomic sample with an array comprising a first probe and a second probe, in which nicking results in less binding of the denatured sample to the first probe relative to a sample that is not nicked; and d) comparing the amount of hybridization to the first probe to the amount of hybridization to said second probe, in which decreased binding of the denatured genomic samples to the first probe relative to the second probe indicates that the first allele of the SNP is present.

Abstract: A mass spectrometer and method for operating the same. The mass spectrometer includes a vacuum chamber and an input port that receives ions to be analyzed in the mass spectrometer. The chamber is adapted to operate at a pressure less than a first pressure, and includes a wall that separates the chamber from an environment outside the chamber at atmospheric pressure. The input port provides a pressure drop between the outside environment at a second pressure and the chamber. The input port includes a plurality of channels, each channel having first and second electrodes arranged on opposing surfaces of that channel and having first and second ends. The first end of each channel is at a pressure equal to the first pressure and the second end is at a pressure less than the second pressure.

Abstract: A high-vacuum pump comprises a plurality of pumping stages, each comprising a plurality of mutually cooperating elements, including at least one rotating rotor element and one stationary stator element. At least one of the elements of at least one of the pumping stages is made of a plastic material reinforced with short fibres, dispersed in chaotic and substantially random manner inside the matrix of plastic material. Use of a plastic material reinforced with short fibres allows making the at least one element by injection molding and allows manufacturing the vacuum pump with considerably reduced production costs if compared to the conventional vacuum pumps.