PrimeSurface cultureware are ultralow attachment (ULA) dishes and plates from FUJIFILM Wako Chemicals U.S.A. that promote scaffold-free, self-assembly of spheroid formation. The plates are precoated with an ultrahydrophilic polymer that enables spontaneous spheroid formation of uniform size and shape. Their high optical clarity makes the plates suitable for brightfield imaging and confocal microscopy. In addition to the widely used 96-well U bottom plate, 96-well plates are also available in V and M bottom, giving scientists the option of forming tighter spheroids that are needed for specific cell types. For high-throughput screening (HTS) needs, 384-well plates are available in clear and white.