A base assembly includes an imaging sensor having a sensor surface to receive a sample, and a platform connected to the base assembly. The base assembly includes (a) an aperture configured to receive a lid surface of a lid in a position to define an imaging space between the sensor surface and the lid surface and (b) a movement portion movable toward and away from the base assembly. The platform and the base assembly are configured to limit contact between the sample and the base assembly other than at the sensor surface.