Three-dimensional (3D) microtissues present an alternative in vitro system for ADME and Toxicology screening. The prevailing method to culture scaffold-free 3D microtissues has been the hanging drop technique, in which a droplet of medium is suspended in a specialised plate, allowing cell aggregation and formation of a microtissue spheroid. Corning Life Sciences have developed an alternative technique for 3D microtissue cell culture that uses rounded-bottom plates coated with a proprietary Ultra-Low Attachment surface.
A comparison study of human liver microtissues cultured in hanging drop and Ultra-Low Attachment plates was conducted as part of the development process. Performance of the microtissues in terms of uniformity, longevity, and metabolic activity was very similar between the two models. However, the real advantage of the Corning Ultra-Low Attachment plates became evident during microtissue analysis.
The plates themselves are 96-well, and each well is opaque with a clear, rounded bottom. The opacity of the well walls reduces interference and cross-talk of fluorescent dyes in neighbouring wells, providing cleaner, more reliable images. The fact that the microtissues are cultured directly in the wells means that they are centrally positioned because the wells have rounded bottoms. Microtissue spheroids cultured in hanging drops must be transferred to a plate prior to imaging, leading to inconsistent placement in the wells, which causes poor image quality. The consistent, predictable placement of spheroids cultured in-well yields superior image quality and more reliable analytical capability.