Disclosed are methods of selectively analyzing a nucleic acid in a sample. The method includes receiving a wireless communication from the mobile unit, where the wireless communication is under a wireless communications protocol that does not provide for handoff of communications links between base station units. When the rotating member is rotated to a first position, the unfolded supporting member supports the device in a first orientation; when the rotating member is rotated to a second position, the supporting member supports the device in a second orientation different from the first orientation. The clinical NMR analyzers can be remotely accessed to evaluate linearity and temperature compensation adjustments. This causes a current to flow mainly through the transistor M1, which improves linearity of a voltage to be rectified.