How do I know when I have inserted the stoppers correctly when using the Oris™ Assembly Kits?

The tip of a properly inserted stopper will create a bull’s-eye pattern at the bottom of the well. To view this bull’s-eye pattern, turn the plate over after inserting the stoppers and tilt the plate at an angle. You will be able to see this bull’s-eye pattern in the center of each well through the clear bottom surface. Stoppers that have not sealed well can be re-inserted until the tip is properly placed. See a video of the technique here.