摘要:
An array-based method for performing SNP analysis is provided. In certain embodiments, the method may comprise: a) contacting a labeled genomic sample with an array comprising a first SNP-detecting oligonucleotide and a second SNP-detecting oligonucleotide that differ from each other by a single nucleotide, under hybridization conditions that provide binding equilibrium; and b) evaluating a SNP of said labeled genomic sample by comparing: i. binding of the labeled genomic sample to the first SNP-detecting oligonucleotide and ii. binding of the labeled genomic sample to said second SNP-detecting oligonucleotide.
摘要:
A method of estimating the allele-specific copy number of a SNP in a test genome is provided. In certain embodiments, the method involves: a) calculating a plurality of probability distribution functions that fit a plurality of log ratios indicating which alleles of a plurality of single nucleotide polymorphisms (SNPs) are present in diploid regions of a test and reference genome; and b) estimating the allele-specific copy number of a SNP of the test genome using said plurality of probability distribution functions.
摘要:
A test system includes an optical medium, a binding agent capable of capturing a target complex, and a light detector. The optical medium provides a light path, and the binding agent is positioned to hold the target complex in an evanescent field created by propagation of light along the light path. The complex interacts with the evanescent field and emits light that the detector positioned to detect. The optical medium and the detector can be included in an optical integrated circuit where detected light passes through the optical medium transverse to the direction of the light path.
摘要:
A test system includes an optical medium, a binding agent capable of capturing a target complex, and a light detector. The optical medium provides a light path, and the binding agent is positioned to hold the target complex in an evanescent field created by propagation of light along the light path. The complex interacts with the evanescent field and emits light that the detector positioned to detect. The optical medium and the detector can be included in an optical integrated circuit where detected light passes through the optical medium transverse to the direction of the light path.
摘要:
Methods and systems for identifying and selecting nucleic acid probes for detecting a target with a nucleic acid probe array or comparative genome hybridization microarray, comprising selecting a plurality of potential target sequences, generating a plurality of candidate probes from the target sequences, filtering the plurality of candidate probes by analyzing candidate probes for selected probe properties in silico. Microarrays comprising probes selected by the methods of the invention are particularly useful for comparative genome hybridization and location analysis.
摘要:
A technique for making precise spectrophotometric measurements illuminates a sample with two or more modulated light sources at two or more, typically closely spaced, wavelengths. Light from the sources is combined, homogenized, and directed to the sample, and the light from the sample is collected and detected by a photodetector. The optical output powers of two sources are modulated with the same periodicity and with a reversed amplitude. Variations in the concentrations of species in the sample affect the modulation amplitude representing the sum of the optical powers from two sources in such a way as to produce an output signal. That output signal, based on an electrical component varying with a periodicity at the fundamental frequency, provides a measure of the difference in the transmissions (or other optical properties) of the sample at the two wavelengths. Feedback methods, such as null-point detection, provide stable, sensitive measurements. Wavelength-division multiplexing--required for simultaneous measurements at many wavelengths--is achieved by modulating different pairs of sources at different frequencies.
摘要:
A sample probe includes a tip including a distal end for penetrating a cellular membrane, an opening located at or proximal to the distal end, and tip microchannels extending through the tip and communicating with the opening; and a body adjoining the tip and including body microchannels, wherein at least one of the body microchannels communicates with at least one of the tip microchannels. A method for sampling intracellular material includes inserting a probe tip through a cellular membrane; aspirating intracellular material from the cell, through an opening of the tip, and into a first microchannel of the tip; flowing isolator fluid from a second microchannel of the tip into the first microchannel to form a plug of intracellular material; and aspirating the plug and the isolator fluid through the first microchannel.
摘要:
Methods for substantially improved detection and analysis in nucleic acid hybridization assays are described. The methods provide the reliable estimation of background signal which derives primarily from nonspecific hybridization. The invention is useful in chemical, biological, medical and diagnostic techniques, as well as for drug discovery.
摘要:
A method and system for extracting data signals from a scanned image resulting from optical, radiometric, or other types of analysis of a molecular array. The positions of corner features are first located. Then, an initial feature coordinate grid is determined from the positions of the corner features. A refined feature coordinate grid is then calculated based on the positions of strong features, and is used to identify the positions of weak features and the positions of the local background regions surrounding all features. Finally, signal intensity values are extracted from the features and their respective local background regions in the scanned image, and background-subtracted signal intensity values, background-subtracted and normalized signal intensity ratios, and variability information and confidence intervals are determined based on the extracted values.
摘要:
Apparatus and methods are disclosed for imaging surfaces that comprise a sample. One embodiment of the present invention is an imaging apparatus comprising a holder for a surface, a light source adapted to illuminate the surface, a diffractive element between the holder and the light source and an imaging detector adapted to receive light from the surface. In a method for imaging a surface comprising a plurality of discrete features, light is selectively diffracted on to one or more predetermined features of the surface at a predetermined point in time. This step is repeated until substantially all of the features on the surface are illuminated. Light is detected from the surface to thereby image the surface.