Abstract: An acoustic sensor detects binding of a nucleic acid analyte in an impure liquid sample by measurement of the energy of the acoustic wave resulting from the binding of the nucleic acid target to the sensor surface. The analysis may be preceded by carrying out a nucleic acid amplification procedure in situ on a crude or impure biological sample and the analysis is tolerant of the presence of reagents or by-products of the amplification procedure, and also materials present from the initial biological sample.

Abstract: Method and apparatus for performing a real-time colorimetric nucleic acid amplification assay wherein the heating of the liquid sample comprised in a reaction tube is carried out by bringing the bottom of the tube in thermal contact with a heating element. The real-time monitoring of the content of the reaction tube is carried out visually through the side wall of the tube, preferably by using a camera.

Abstract: Disclosed is a method of investigating the conformation of biomolecules or changes in the conformation of biomolecules as a result of an interaction, in which biomolecules from a sample of biomolecules are adhered discretely to the sensing surface of an acoustic wave sensor operating in a liquid, and a conformation parameter which is related to the conformation of the biomolecules from the said sample which are adhered discretely to the sensing surface, but substantially independent of the resulting change in mass loading of the sensing surface, is calculated from the resulting change in the output signals of the acoustic wave sensor. The conformation parameter may the acoustic ratio or a parameter which is directly related to the acoustic ratio.

Abstract: Disclosed is a method of investigating the conformation of biomolecules or changes in the conformation of biomolecules as a result of an interaction, in which biomolecules from a sample of biomolecules are adhered discretely to the sensing surface of an acoustic wave sensor operating in a liquid, and a conformation parameter which is related to the conformation of the biomolecules from the said sample which are adhered discretely to the sensing surface, but substantially independent of the resulting change in mass loading of the sensing surface, is calculated from the resulting change in the output signals of the acoustic wave sensor. The conformation parameter may the acoustic ratio or a parameter which is directly related to the acoustic ratio.

Abstract: A chemical sensor includes a piezoelectric support (1) capable of supporting a shear horizontal wave provided on its surface with an electrode (2,3). The sensor is characterized in that the surface of the piezoelectric support (1) including the region bearing the electrode (2,3) is covered by a layer of dielectric material (9) of thickness 0.5 to 20 microns. The piezoelectric support (1) is preferably a single crystal. The dielectric layer (1) may be of, for example, silicon dioxide or a suitable polymer, and preferably has a thickness of between 0.5 and 5 .mu.m.