Contact plate

A plate with a raised, convex agar surface, typically 55 mm in diameter (about 25 cm²), pressed onto a flat surface to sample micro-organisms. The agar usually contains neutralisers such as lecithin and polysorbate 80 to inactivate disinfectant residues. Contact plates are used for surfaces, gowns and gloves, applied with even pressure for a few seconds at the end of operations. The surface is wiped afterwards to remove agar residue.