A CMOS image sensor is provided. In one form, the delay mechanism includes a shuttle for the syringe, a follower, a locking member, a damping compound between the follower and a supporting surface to dampen rotation of the follower relative to the shuttle, and a dual functioning biasing member acting between the shuttle and the follower. The target molecule is preferably DNA. The shaking loosens the developing agent so as to maintain its fluidity, thereby avoiding faint image formation. The indicator is driven by the interface to show users that the accessible memory card is performing an access operation when the controller gives commands to the accessible memory card.