The present invention discloses a test device including a support member; a top member mounted to the support member, wherein in the support member and the top member are configured such that they together define a discrete chamber. The discrete chamber includes a first well region including at least one first well; a second well region including at least one second well; and a channel region including at least one channel connecting the first well region and the second well region with one another. The second region is preferably horizontally offset with respect to the first well region in a test orientation of the device.