Abstract: A fluorescence microtitre plate reader comprises a plate reader body (2) having a base (3), top (5) and sidewalls (4), the top of the plate reader comprising at least one seat (6) dimensioned for receipt of a microtitre plate (7), the at least one seat defining an aperture (8) in the top of the plate that substantially corresponds to a base of the plate. The plate reader also includes means for illuminating wells of a microtitre plate with light from beneath the plate having an excitation wavelength, and a camera (10) and lens (11) assembly for capturing light emitted by the wells of the microtitre plate and generating a digital image, in which regions of light intensity of the image correspond to wells of the microtitre plate.