Embodiments disclose a device for testing biological specimen. The device includes a sample carrier and a detachable cover. The sample carrier includes a specimen holding area. The detachable cover is placed on top of the specimen holding area. The detachable cover includes a magnifying component configured to align with the specimen holding area. The focal length of the magnifying component is from 0.1 mm to 8.5 mm. The magnifying component has a linear magnification ratio of at least 1.