Light sealing gasket and piston arrangement for analytical laboratory micro-titre apparatus undertaking quantitative measurement of fluorescence and photoluminesence reactions

摘要

A light measurement unit has a housing (10) containing a positioning device (12) for sequentially locating matrix arranged cells (22) on a micro-titre plate (14) at a light measuring station. A photo-multiplier tube (16) is arranged to receive the light emitted from the mouth of each cell presented to the measuring station, and has an entry plate (52) to shield the measured cell from radiation originating in neighbouring cells. The photo-multiplier entry plate aperture (66) has a resilient elastic annular insert (68) for engaging the lip (24) of the measured cell, against which it is urged by a piston (20), but with the photo-multiplier tube itself remaining stationary. The vertically emergent light from the measured cell passes through the entry port (52) and is reflected into the photo-multiplier tube (16) by a concave reflecting surface (56). A fibre optics type light source (63) may be mounted inside the entry plate aperture (66) for initiation chemiluminescence or excitation of fluorescence.