An information storage medium having a plurality of information storage layers, each of which includes an optimal power control area for obtaining an optimal recording condition, wherein OPC areas in odd-numbered and even-numbered information storage layers are disposed not to face each other and not to contact each other, or partially overlap each other and lock out use of the overlapped portion. In turn, the reference time, in one embodiment, may be used to determine other navigational information. , glucose oxidase, and a mediator effective to transfer electrons from the enzyme.