Patent ID: 8850903

Claim:
A method for aspirating and dispensing liquids through a liquid holding tip from or to a target, the liquid holding tip forming a replaceable part of a liquid handling device, the method comprising the steps of: a. positioning the liquid holding tip with respect to the target, wherein the liquid holding tip includes a tip wall at least partially including a waveguide-quality material integral with or adjacent to the tip wall; b. transmitting at least one signal within the waveguide quality material to the target, wherein the at least one signal includes one or more indicia of position of the tip with respect to the target; c. detecting the at least one signal; and d. determining from the at least one detected signal one or more of: (1) whether the tip is properly attached to the liquid handling device; (2) whether the proper type of tip is connected to the liquid handling device; (3) whether the tip has contacted the surface of a liquid sample of the target, both when the tip is empty for aspiration and when the tip contains a liquid aliquot for dispensation; (4) whether the immersion depth of the tip in the liquid sample is acceptable; (5) whether the liquid aliquot is present in the tip; and (6) whether liquid is not present in the tip.