The invention relates to an arrangement for studying samples and a substrate for samples. The arrangement comprises a frame (1) providing a basis for at least two samples. The frame (1) may be provided with at least two light sources (4a - 4i) for emitting light. The arrangement further comprises at least one substrate (7) for samples and at least two sensors (8) for detecting how much the samples emit or absorb light. The substrate (7) may comprise a bottom (12) made of quartz glass and having a nano coating.
