Patent ID: 8129175

Claim:
An apparatus for exposing cells to a test compound solution diffused from a point source to determine whether the test compound solution induces progressive cell activity response in the cells, the apparatus comprising: a substrate; a cover applied over the substrate such that a passageway is defined between the cover and the substrate, wherein the cover has an outer perimeter, wherein the cover defines an opening inside the outer perimeter, and wherein the opening is in fluid communication with the passageway; and a hydrophobic barrier disposed within the passageway, wherein the hydrophobic barrier defines a test site perimeter of a test site, wherein the test site perimeter is disposed within the outer perimeter of the cover when the cover is viewed from a plan view perpendicular to a plane defined by the cover, wherein the opening is disposed within the test site perimeter when the cover is viewed from the plan view, wherein the substrate, the cover, and the hydrophobic barrier are configured to contain the cells within the test site, wherein the hydrophobic barrier limits passage of liquid outside of the test site and allows passage of gas outside of the test site, and wherein the opening is the only opening defined by the cover within the test site perimeter.