A system for use in spectral analysis procedures can include a slide and a holder for carrying the slide. The slide includes a substrate forming a plurality of wells that are recessed relative to a surface of the substrate. Each of the wells forms a sample region that is recessed by a sample depth from the surface and a trough region that is recessed by a trough depth from the surface, the trough depth being greater than the sample depth. The holder includes a body defining a cavity between a first side and a second side of the body, a port for receiving the slide into the cavity, one or more first fenestrations on the first side, and one or more second fenestrations on the second side.