The present invention provides an insertion device and method for implanting a biosensor into a patient subject. In one embodiment, a biosensor is stored in the instrument's hydration chamber which enables the biosensor to maintain proper hydration and sterilization prior to insertion. The instrument further includes a plunger that travels along a channel within the support device. After the biosensor is placed into the channel, the user pushes the plunger causing the biosensor to move through the channel and a hollow tube and into the patient subject. The present invention also provides for packaging and storing a biosensor and insertion device so that the biosensor is hydrated and sterile prior to insertion.