a well plate of non - unitary construction . the well plate is constructed from a first part of interconnected tubes that define the side walls of each well and a second part defining the well bases . the hydrophobicity of the first part is selected to suppress meniscus formation in the wells , thereby assisting optical characterization of samples in the wells , in particular by phase contrast microscopy . this can be achieved by using a natural cycloolefin copolymer which is not subjected to the usual plasma treatment to improve its wetting . the second part is formed of a single transparent sheet of hydrophilic material , such as a cop , which is bonded to the first part , for example ultrasonically .