Abstract: An optical device for determining the presence of a first nucleic acid in a sample comprising a second nucleic acid complementary to the first nucleic acid and able to hybridize with the first nucleic acid under hybridizing conditions, the second nucleic acid being bonded to a solid support, wherein the solid support is formed as a light reflecting surface having a first thickness when bonded to the second nucleic acid, and wherein the light reflecting surface has a second thickness, wherein the first and second nucleic acids are hybridized, and the first and second thicknesses can be distinguished by their effect on the light reflecting properties of said light reflecting surface independent of any label present on the first nucleic acid.

Abstract: An optical device for determining the presence of a first nucleic acid in a sample comprising a second nucleic acid complementary to the first nucleic acid and able to hybridize with the first nucleic acid under hybridizing conditions, the second nucleic acid being bonded to a solid support, wherein the solid support is formed as a light reflecting surface having a first thickness when bonded to the second nucleic acid, and wherein the light reflecting surface has a second thickness, wherein the first and second nucleic acids are hybridized, and the first and second thicknesses can be distinguished by their effect on the light reflecting properties of said light reflecting surface independent of any label present on the first nucleic acid.

Abstract: A process for providing a surface of glass, silicon, aluminum or silicone rubber of an article useful within medicine with a bicompatible surface layer. Said surface is reacted (after oxidation when required) with a silane containing at least one epoxy group and the surface thus treated is then reacted with a polysaccharide containing at least one hydroxyl group. The invention also relates to an article exhibiting a biocompatible surface layer of a polysaccharide containing at least one hydroxyl group, which polysaccharide is covalently bound to a surface of glass, silicon, aluminum or silicone rubber of the article by means of a silane.

Abstract: In an ellipsometric method and apparatus which, in order to increase the degree of measuring accuracy, uses the principle of comparative ellipsometry in measuring a characteristic such as a layer thickness, a reference surface is divided into first and second equal surface portions with respectively different reflection characteristics which are in substantially symmetrical relationship to the reflection characteristics of the testpiece, the surface portions preferably comprising two different tapering surface layers extending in parallel relationship to each other.

Abstract: An ellipsometric method and apparatus for studying physical properties of a testpiece provides that during the measuring operation the angular positions of a polarizing means and an analyzing means disposed upstream and downstream of the testpiece remain fixed. Two or more discrete, mutually different predetermined states of polarization of the radiation employed are produced between the polarizing means and the testpiece and/or between the testpiece and the analyzing means, by polarization modulating elements which are disposed in the path of the radiation. In each discrete state of polarization, the intensity of the radiation which is polarized in the analyzer is measured and evaluated for determining the polarization properties of the testpiece in a computer.

Abstract: A process for providing a surface of glass, silicon, aluminum or silicone rubber of an article useful within medicine with a biocompatible surface layer. Said surface is reacted (after oxidation when required) with a silane containing at least one epoxy group and the surface thus treated is then reacted with a polysaccharide containing at least one hydroxyl group. The invention also relates to an article exhibiting a biocompatible surface layer of a polysaccharide containing at least one hydroxyl group, which polysaccharide is covalently bound to a surface of glass, silicon, aluminum or silicone rubber of the article by means of a silane.

Abstract: A member for detecting and/or measuring the level of concentration of a chemical substance in a medium comprises a non-metal substrate bearing a dielectric layer. A detection reactant which is capable of reacting with the substance to be detected is put on the dielectric layer and the assembly is put into the medium to be investigated, whereupon an optically detectable layer of the substance to be detected is formed on the detection reactant.

Abstract: In a method and apparatus for studying surface properties of a testpiece, such as refractive index or thickness of a layer or film on said surface, electromagnetic radiation is directed on to the test surface or a reference surface which has known properties, and reflected on to the other surface. The angle of incidence in respect of the incident radiation, in relation to the respective surfaces, are the same, and the surfaces are so arranged that when the radiation is reflected from one surface on to the other, the parallel polarization component of the first reflection is the perpendicular component of the second reflection. Radiation in the same state of polarization as before the first reflection is extinguished by an analyzer, providing for point-to-point comparison between the two surfaces.