Abstract: A plate assembly includes a first sample holder for receiving a plurality of samples, wherein the first sample holder is a transparent foil sheet and includes a plurality of cuvettes configured to receive a sample. A sample fixing plate for positioning the samples is placed in the cuvettes, wherein the sample fixing plate includes a plurality of inserts to be inserted into the cuvettes such that per cuvette a chamber is formed between the first sample holder and the inserted sample fixing plate. The chamber ensures the structural integrity of a single sample. At least one slot is formed next to each insert to allow the transmission of light emitted by the light-sheet microscope. The sample fixing plate also includes at least two opposite magnets and a sample holder frame for receiving the sample holder and the sample fixing plate fitted to each other.