Abstract:
A method is provided for preparing small (less than 2000 .ANG.) lipid vesicles in commercial quantities by microemulsifying lipid compositions using very high shear forces generated in a homogenizing apparatus operated at high pressures at a selected temperature. These vesicles are suitable for various biological applications including targeting of tumors in a body for diagnosis and treatment.
Abstract:
High throughput analytical systems and methods employing multiple liquid phase separation process regions coupled to a common mass spectrometer are provided. Disclosed systems and methods permits parallel separation and parallel storage of discrete eluate fractions, followed by sequential discharge and ionization of previously stored eluate portions to yield a composite ion stream containing the sequential series of eluate portions, followed by mass analysis of the ion stream. A common manifold may receive ions and utilize pressurized gas or ion gating to direct ions within the manifold toward the mass spectrometer inlet.
Abstract:
Devices and methods are provided for precise reduction of arrays of microspots. A pulse jetting device is employed having a capillary of micron dimensions, with a portion of the capillary proximal to the jetting orifice circumferentially surrounded by a piezoelectric transducer. By appropriate design of the capillary, orifice and piezoelectric transducer, droplets can be formed on a surface, separated by as little as 80 microns center-to-center, and having at least about a 15 micron spacing at the border. The subject substrate arrays can be used for providing miniaturized arrays of reagents, such as nucleic acids, for detecting the presence of homologous sequences in a sample.
Abstract:
An apparatus for the automated synthesis of molecular arrays. A jetting device is employed along with a reaction chamber to dispense reagents used in the synthesis onto the substrate. A positioning system moves the substrate from the jet to the reaction chamber. A controller controls the movement of the substrate and the application of the reagents so that the synthesis is carried out according to a pre-determined procedure. The apparatus will synthesize nucleotides in an array of micron-size spots according to a pattern selected by the operator immediately prior to synthesis.
Abstract:
Solvent vehicles and methods of their use in the pulse jet delivery of reagents in automated oligonucleotide synthesis by the solid-phase phosphoramidite method are provided. For pulse jet delivery of the activated monomer, acetonitrile in combination with at least one stabilizer co-solvent is employed as the solvent vehicle, where the stabilizer co-solvent is an inert, organic solvent having a boiling point of at least 100.degree. C. For pulse jet delivery of the detritylation reagent, a mono- or disubstituted methane is employed as the solvent vehicle, where substituents have a molecular weight greater than 36 daltons. Use of the solvent vehicles according to the subject invention provides for reduced reagent precipitation in the pulse jet tubes and improved results.
Abstract:
The synchronous sampling scanning force microscope includes a reflective cantilever arm having a free end which is oscillated at a frequency different from the resonance frequency of the cantilever arm. The motion of the oscillating cantilever arm is measured, to generate a deflection signal indicative of the amplitude of deflection or phase shift of the cantilever arm. Selected portions of cycles of the output signal are sampled, for generating output signal data indicative of deflection of the near and far excursions of the probe. The method and apparatus permit monitoring of compliance of the surface of the specimen by multiple sampling at a rate greater than the period of oscillation of the cantilever probe of the microscope.
Abstract:
An immunoassay method for detection of antigen is disclosed. The method employs complement mediated lysis of vesicles loaded with In-111 or other gamma-emitting cation, and quantitative detection of the lysis by gamma-ray perturbed angular correlation (PAC) spectroscopy. The vesicles are labeled with a substance competitive to the antigen to be measured, and the concentration of the antigen in the sample measured by assessing the diminution in lysis due to the presence of the competing antigen.The method may also be used to assess the immunologic competence of a subject by injecting suitably sensitized vesicles and monitoring the in vivo lysis pattern by (PAC).
Abstract:
Lipid vesicles comprising a lipid bilayer which includes analogs of cell-surface receptors such as dicetyl phosphate; stearylamine; 6-(5-cholesten-3.beta.-yloxy) hexyl 1-thio-.beta.-L-fucopyranoside; 6-(5-cholesten-3.beta.-yloxy) hexyl 1-thio-.beta.-D-galactopyranoside; 6-(5-cholesten-3.beta.-yloxy)hexyl 1-thio-.alpha.-D-mannopyranoside; 6-(5-cholesten-3-yloxy)hexyl 2-acetamido-2-deoxy-1-thio-.beta.-D-galactopyranoside; 6-(5-cholesten-3.beta.-yloxy)hexyl 6-amino-6-deoxy-1-thio-.beta.-D-galactopyranoside; or 6-(5-cholesten-3.beta.-yloxy)hexyl 6-amino-6-deoxy-1-thio-.alpha.-D-mannopyranoside; cholesterol and distearoyl phospatidylcholine, and an effective amount of physiologically compatible radioactive tracer, cytotoxic or therapeutic agent as a part of the vesicles. The vesicles of this invention can be administered to the human host and have been found to release the contents of the vesicles in a predetermined manner, i.e., controlled release, and in some cases, to be rapidly concentrated in the lymphatic system and/or liver, lungs or spleen of the host.
Abstract:
A scanning force microscope is disclosed which includes integrated optics for viewing the optical lever arm, probe and sample to be examined. The scanning force microscope includes a simplified mounting of laser and related adjustments and the locating of a detector independent of the scanner, to improve ease of handling and providing convenient locations for adjustments. In one preferred embodiment of the scanning force microscope, the surface of samples may be imaged while the cantilever portion of the scanner is immersed in liquids without special set-up or special adapters.
Abstract:
A scanning probe microscope is disclosed which includes a pivotally mounted scanning assembly for scanning a surface of a sample. A sensing assembly is mounted relative to the scanning assembly and is positioned for sensing the surface topography of the sample. The scanning assembly includes a bore extending vertically through the scanning assembly which allows direct overhead viewing of the sensing assembly and the sample. The scanning assembly is pivotally mounted by a hollow pivot assembly which permits both the sensing assembly and the sample to be viewed through the scanning assembly when aligning the sensing assembly with the sample. The hollow pivot assembly also allows a user to optically view the sample from directly overhead with an optical microscope or charge coupled device.