摘要:
Disclosed herein are methods, kits, and equipment for purifying single stranded circular DNA and then using the DNA for DNA sequencing purposes. Templates are provided with an insert having a hybridization region. An elongated oligonucleotide has two regions that are complementary to the insert and the oligo is bound to a magnetic anchor. The oligo hybridizes to the insert on two sides to form a stable triple helix complex. The anchor can then be used to drag the template out of solution using a magnet. The system can purify sequencing templates, and if desired the triple helix complex can be opened up to a double helix so that the oligonucleotide will act as a primer for further DNA synthesis.
摘要:
The present invention provides systems, devices, device components and structures for modulating the intensity and/or energies of electrons, including a beam of incident electrons. In some embodiments, for example, the present invention provides nano-structured semiconductor membrane structures capable of generating secondary electron emission. Nano-structured semiconductor membranes of this aspect of the present invention include membranes having an array of nanopillar structures capable of providing electron emission for amplification, filtering and/or detection of incident radiation, for example secondary electron emission and/or field emission. Nano-structured semiconductor membranes of the present invention are useful as converters wherein interaction of incident primary electrons and nanopillars of the nanopillar array generates secondary emission. Nano-structured semiconductor membranes of this aspect of the present invention are also useful as directed charge amplifiers wherein secondary emission from a nanopillar array provides gain functionality for increasing the intensity of radiation comprising incident electrons.
摘要:
The present invention relates to systems, compositions, and methods for the detection and characterization of nucleic acid sequences and variations in nucleic acid sequences. The present invention relates to methods for attaching nucleic acids to solid supports and modifying nucleic acids. For example, in some embodiments, the 5′ nuclease activity of a cleavage agent is used to cleave a cleavage structure formed on the solid support, the occurrence of the cleavage event indicating the presence of specific nucleic acid sequences.
摘要:
A horizontal electrophoresis assembly is described which is designed to utilize very thin gels of polyacrylamide. The assembly allows for water cooling of the gel during electrophoresis so that higher voltages can be applied to the gel without polymer degradation. The gel mold is made from a set of glass plates which are clamped into place defining a gel mold between them. In one embodiment, the site of field introduction is separated from the site of sample introduction so that the electric field is generally linear at the region of sample introduction.
摘要:
A system for the electrophoretic analysis of DNA fragments produced in DNA sequencing operations comprising: a source of chromophore or fluorescent tagged DNA fragments; a zone for contacting an electrophoresis gel; means for introducing said tagged DNA fragments to said zone; and photometric means for monitoring said tagged DNA fragments as they move through said gel.
摘要:
An apparatus is disclosed to optically determine which of four fluorophores is attached to a band of DNA molecules on an electrophoresis gel. The apparatus includes four separate band pass interference filters and four wedge prisms to create four discrete areas of light on a detector. Digital comparison of the relative intensity of light sensed in the four discrete areas determines the identity of the excited fluorophore.
摘要:
Apparatus and method for detecting the occurrence of a dial pulse signal in a telephone circuit. Transient signals within the frequency range of possible dial pulse signals are detected, and the amplitude of the detected signals are compared with a predetermined amplitude level. A first time period and a second time period are initiated in response to a first detected signal which exceeds a certain initial reference amplitude, with the duration of the first time period being less than the interval between the two consecutive transient pulse signals to be expected of a true dial pulse signal. The duration of the second time period is substantially equal to the period of a true dial pulse signal. A received signal resembling a dial pulse signal is detected during the first period only if the amplitude of such signal exceeds a second reference amplitude which is greater than the initial reference amplitude. A second apparent dial pulse transient signal condition, occurring after the termination of the first time period but before the termination of the second time period, is interpreted as the occurrence of a true dial pulse signal, in response to which a corresponding dial pulse output signal is produced. A second apparent dial pulse transient signal condition occurring in the first time period, however, merely extends the duration of the first time period and provides no dial pulse output signal. An amplitude comparison circuit automatically adjusts the reference amplitude in response to the signal level of the circuit providing input signals to the apparatus.
摘要:
SPR-compatible substrates for high density microarray fabrication and analyses are provided. Novel carbon-on-metal thin film substrate architecture permits the integration of surface plasmon resonance detection with photolithographically fabricated biomolecule arrays for the analysis of biomolecular interactions. The utility of the technology is shown in the analysis of specific DNA-DNA, DNA-RNA and DNA-protein binding interactions. These new substrates may be used to determine the secondary structure of RNA molecules, to probe the sequence-specific binding kinetics and affinity of proteins and small molecules, and as substrates for small-molecule combinatorial chemistry platforms for drug discovery applications.
摘要:
Relative quantification of metabolites by Electrospray Ionization Mass Spectrometry (ESI-MS) requiring a mechanism for simultaneous analysis of multiple analytes in two or more samples. Labeling reagents that are reactive to particular compound classes and differ only in their isotopic kit facilitating relative quantification and providing tangible evidence for the existence of specific functional groups. Heavy and light isotopic forms of methylacetimidate were synthesized and used as labeling reagents for quantification of amine-containing molecules, such as biological samples. Heavy and light isotopic forms of formaldehyde and cholamine were also synthesized and used independently as labeling reagents for quantification of amine-containing and carboxylic acid-containing molecules, such as found in biological samples. Advantageously, the labeled end-products are positively charged under normal acidic conditions involving conventional Liquid Chromatography Mass Spectrometry (LC/MS) applications. Labeled primary and secondary amine and carboxylic acid end-products also generated higher signals concerning mass-spectra than pre-cursor molecules and improved sensitivity. Improved accuracy concerning relative quantification was achieved by mixing heavy and light labeled Arabidopsis extracts in different ratios. Labeling strategy was further employed to ascertain differences in the amounts of amine-containing metabolites for two strains of Arabidopsis seeds.
摘要:
The compounds of the invention include novel linking agents comprising 2-substituted-3-protected-1,3,2-oxazaphosphacycloalkanes and their phosphoramidite precursors. The compounds of the invention further include conjugates of the above linking agents with oligonucleotides and polymer supports. The compounds of the present invention are useful for linking organic moieties, such as fluorescent or chromogenic dyes, to polymer supports and oligonucleotides, particularly single- and double-stranded DNA and RNA fragments.