Abstract: According to at least one aspect, the invention provides a filter assembly (100) comprising a tubular housing and a filter device (70) locatable to extend longitudinally within the housing. The filter device (70) comprises a lattice structure of crossing internal and external elongated elements (18, 20). The lattice structure comprises an arrangement of pores (22), and the external elongated elements (20) are presented outwardly of the filter device (70) with respect to the plane of the pores, thereby to provide ribs on the exterior of the lattice which define a shaped channel that will act as a first level filter for larger particles. The external elongated elements are shaped and arranged to provide one or more additional filter levels for smaller particles in advance of said pores, through which yet even smaller particles may pass.

Abstract: According to at least one aspect, the invention provides a filter assembly (100) comprising a tubular housing and a filter device (70) locateable to extend longitudinally within the housing. The filter device (70) comprises a lattice structure of crossing internal and external elongated elements (18, 20). The lattice structure comprises an arrangement of pores (22), and the external elongated elements (20) are presented outwardly of the filter device (70) with respect to the plane of the pores, thereby to provide ribs on the exterior of the lattice which define a shaped channel that will act as a first level filter for larger particles. The external elongated elements are shaped and arranged to provide one or more additional filter levels for smaller particles in advance of said pores, through which yet even smaller particles may pass.

Abstract: The shallower wells of a crystalisation plate in which it is intended to form crystals are part-spherical and of uniform wall thickness. The optical effect of the transparent plastics material from which the plate is moulded counter the distortion of a view through a microscope so that crystals viewed through the microscope appear to be on a flat surface. Associated with the wells are markings so small that they can be read through the microscope, making it unnecessary for the user to take the eye off the microscope to determine the position on the plate.