Abstract: A scanning probe microscope is combined with a laser induced breakdown spectrometer to provide spatially resolved chemical analysis of the surface correlated with the surface topography. Topographical analysis is achieved by scanning a sharp probe across the sample at constant distance from the surface. Chemical analysis is achieved by the means of laser induced breakdown spectroscopy by delivering pulsed laser radiation to the sample surface through the same sharp probe, and consequent collection and analysis of emission spectra from plasma generated on the sample by the laser radiation. The method comprises performing microtopographical analysis of the sample with a scanning probe, selecting a scanned topological site on the sample, generating a plasma plume at the selected scanned topological site, and measuring a spectrum of optical emission from the plasma at the selected scanned topological site.

Abstract: The present invention discloses an improved method and apparatus for analyzing the surface of materials using sub-micron laser desorption gas phase analysis. The method uses a combination of Near-field Optical Microscopy and Time-of Flight Mass Spectroscopy.

Abstract: A method and apparatus are provided for preparing a substrate upon which is located microdrop-sized loci at which chemical compounds are synthesized or diagnostic tests are conducted. The loci are formed by applying microdrops from a dispenser from which a microdrop is pulse fed onto the surface of the substrate.

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: A method and apparatus are provided for preparing a substrate upon which is located microdrop-sized loci at which chemical compounds are synthesized or diagnostic tests are conducted. The loci are formed by applying microdrops from a dispenser from which a microdrop is pulse fed onto the surface of the substrate.

Abstract: Probes for sensing and manipulating microscopic environments and structures, their method of preparation and methods of use are disclosed.

Abstract: Liposomes of a size of less than 200 nanometers target ischemic myocardial tissue and preferentially deliver active agents to infarcted areas.

Abstract: Liposomes of a size of less than 200 nanometers target ischemic myocardial tissue and preferentially deliver active agents to infarcted areas in the absence of antibodies bound to the liposomes to effect the delivery.

Abstract: Compositions for cryopreservation of phosphoglyceride-containing biological and synthetic membranes are provided in which a lipophilic anchor molecule is modified by the attachment of a preferably carbohydrate moiety placed at a predetermined, variable distance from the hydrophobic portion of the molecule by means of a hydrophilic linker unit. A method for the use of the compositions is also provided.

Abstract: Closed, unilamellar vesicles are spontaneously formed by adding a cholesteryl compound substituted with a hydroxyl terminated polyethylene oxide containing 1 to 4 ethylene oxide groups to a polar liquid. Multilamellar vesicles are formed by sonicating a cholesteryl compound containing polyethylene oxide or polyamine side-chains. The vesicles can be utilized to dispense polar, non-polar or ampholphilic compounds.

Abstract: The ability of phosphoglyceride-containing membranes to withstand the disruptive effects of freezing, thawing, or freeze-drying is enhanced when treated with (a) a compound of the formula R-X-R.sub.1, wherein R is a lipid or lipophilic anchor, X is a hydrophilic linker group, and R.sub.1 is a polyalcohol or carbohydrate group, and (b) ascorbic acid.

Abstract: Compositions for cryopreservation of phosphoglyceride-containing biological and synthetic membranes are provided in which a lipophilic anchor molecule is modified by the attachment of a preferably carbohydrate moiety placed at a predetermined, variable distance from the hydrophobic portion of the molecule by means of a hydrophilic linker unit. A method for the use of the compositions is also provided.

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: Unilamellar vesicles comprising a lipid bilayer, an ionophore being incorporated in said lipid bilayer, a chelating agent entrapped within the vesicles, and an effective amount of physiologically compatible cation bound to said chelating agent within the vesicles. Unilamellar vesicles are loaded by incubating the vesicles with the cation, terminating the incubation and recovering the loaded vesicles by chromatography. In some applications of the invention, the cation may be a radioactive tracer, in which case the vesicles can be administered to the human host and observed by scintillation techniques to produce a radioimage which is useful for diagnostic purposes.

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.