A flat panel imaging system for imaging cells provided on a cell medium is disclosed. The system includes a housing having a base portion and a lid that collectively form a closed environment to exclude external sources of light, and a flat panel detector encased in the base portion and having an array of pixels each including a photodiode and transistor. The system also includes a first light source that illuminates cells on the cell medium to excite at least a portion of the cells and cause those cells to generate photons that are captured by the array of pixels and a second light source to illuminate cells on the cell medium with a light different from the light from the first light source and that provides for a capturing of photons representative of photons transmitted through the cells on the cell medium.