Polyethylene, open-ended sample cups designed to function as closed cells with provision for pressure equalization.

Adaptable for micro-sample containment and “thin-layered” sample preparations. Each sample cup consists of a cell, a snap-on ring and a collar. Cell contains two circular thermoplastically sealed depressions. By puncturing one seal, a passageway is established to release entrapped gases or relieve vapor pressure build-up from the sample. Incorporates unique “bead-to-indent” geometry responsible for establishing taut thin-film sample support surface and effecting leak-resistant seals.