A microwell plate comprises a skirt and frame portion having a top surface and a bottom surface, and having a plurality of holes; and a well and deck portion comprising a plurality of wells integrated with a planar deck; wherein the well and deck portion is overmolded or adhered onto the skirt and frame portion such that the plurality of wells extends through the plurality of holes in the top surface of the skirt and frame portion; and wherein the well and deck portion is formed from a thermoplastic composition including a poly(aliphatic ester)-polycarbonate comprising soft block ester units, derived from monomers comprising an alpha, omega C6-20 aliphatic dicarboxylic acid or derivative thereof, a dihydroxyaromatic compound, and a carbonate source.