Optically clear seal specifically developed for optical applications, particularly qPCR. It is non sticky when removed from the packaging; this aids handling when wearing gloves. The adhesive is contained within small capsules, allowing light to pass through to ensure the optical clarity of the seal. When the seal is in position, pressure can be applied to burst the capsules, releasing a strong adhesive only where the seal touches the raised well rims of the plate - the rest of the seal area above the wells remains optically clear.