probe
(prOb)
  1. A slender rod of flexible material, with blunt bulbous tip, used for exploring sinuses, fistulas, other cavities, or wounds.
  2. A device or agent used to detect or explore a substance; e.g., a molecule used to detect the presence of a specific fragment of DNA or RNA or of a specific bacterial colony.
  3. To enter and explore, as with a probe.