Image credit: BioDynamic Devices
Image credit: BioDynamic Devices
A test apparatus is described comprising a housing (12) containing a location at which a sample tray (28) containing a plurality of sample wells (30) can be located, a light box (14) positioned to permit irradiation of the sample tray (28), and an imaging arrangement (34) to permit imaging of the sample tray, wherein the light box (14) comprises a light source (16) including a light guide (18) in the form of a plate (20) of a transparent material and a plurality of light emitting devices (26) provided adjacent at least one edge of the plate (20), wherein a surface of the plate (20) is provided with a plurality of transmitting regions (22) whereby light is transmitted from the plate (20). Corresponding methods of calibration and use of the test apparatus are also described.