Abstract: A three dimensional inverted colloidal crystal scaffold is described which comprises a substrate having at least one well. The scaffold also includes a three dimensional matrix comprising a transparent biocompatible polymeric network containing microspherical voids. The microspherical voids are each connected to at least one other void through inter-connecting pores. Additionally, an apparatus for producing such a colloidal crystal scaffold is described. Methods for making the inverted colloidal crystal scaffold, for using the scaffold and for identifying the effects of a drug, pharmaceutical or toxin on a living cell using the inverted colloidal crystal scaffold are also disclosed.