Use of a cell co-culture device in high throughput screening, said device comprising: a first surface and a second surface below said first surface, wherein said second surface comprises i) a plurality of first wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said first wells and an upper edge of said first end wall of said first wells defining a first depth of said first wells, and in said first wells added first cells and culture medium, and ii) a plurality of second wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said second wells and an upper edge of said second end wall of said second wells defining a second depth of said second wells, and in said second wells added second cells of a different cell type than said first cells and culture medium; wherein said second wells are adjacent with said first wells, and wherein - said second end wall of said first well connects with said bottom wall of said first well and - said first end wall of said second well connects with said bottom wall of said second well to form a physical and fluidic barrier between said first and second wells (12, 26); - at least a portion of said second end wall of said first well and at least a portion of said first end wall of said second well have a height less than said first and second depths forming a channel with parallel first and second side walls (40, 42) and a bottom wall vertically spaced from the first and second surfaces with one channel end connected to the second end wall of said first well and another end connected to the first end wall of the second well; - wherein further said channel contains on said one end and on said another end an inset capillary channel set within, but not through walls and, that extends down from wall creating walls or parallel to wall and walls and perpendicular to wall, said inset capillary channel having a width under 1000 μm. a first surface and a second surface below said first surface, wherein said second surface comprises i) a plurality of first wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said first wells and an upper edge of said first end wall of said first wells defining a first depth of said first wells, and in said first wells added first cells and culture medium, and ii) a plurality of second wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said second wells and an upper edge of said second end wall of said second wells defining a second depth of said second wells, and in said second wells added second cells of a different cell type than said first cells and culture medium; i) a plurality of first wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said first wells and an upper edge of said first end wall of said first wells defining a first depth of said first wells, and in said first wells added first cells and culture medium, and ii) a plurality of second wells with a first end wall and a second end wall and a bottom wall, wherein a distance from said bottom wall of said second wells and an upper edge of said second end wall of said second wells defining a second depth of said second wells, and in said second wells added second cells of a different cell type than said first cells and culture medium; wherein said second wells are adjacent with said first wells, and wherein - said second end wall of said first well connects with said bottom wall of said first well and - said first end wall of said second well connects with said bottom wall of said second well - said second end wall of said first well connects with said bottom wall of said first well and - said first end wall of said second well connects with said bottom wall of said second well to form a physical and fluidic barrier between said first and second wells (12, 26); - at least a portion of said second end wall of said first well and at least a portion of said first end wall of said second well have a height less than said first and second depths forming a channel with parallel first and second side walls (40, 42) and a bottom wall vertically spaced from the first and second surfaces with one channel end connected to the second end wall of said first well and another end connected to the first end wall of the second well; - wherein further said channel contains on said one end and on said another end an inset capillary channel set within, but not through walls and, that extends down from wall creating walls or parallel to wall and walls and perpendicular to wall, said inset capillary channel having a width under 1000 μm. - at least a portion of said second end wall of said first well and at least a portion of said first end wall of said second well have a height less than said first and second depths forming a channel with parallel first and second side walls (40, 42) and a bottom wall vertically spaced from the first and second surfaces with one channel end connected to the second end wall of said first well and another end connected to the first end wall of the second well; - wherein further said channel contains on said one end and on said another end an inset capillary channel set within, but not through walls and, that extends down from wall creating walls or parallel to wall and walls and perpendicular to wall, said inset capillary channel having a width under 1000 μm.