Patent ID: 8016997

Claim:
A method for determining the time of sample application, and triggering the start of an electrochemical assay conducted in an electrochemical test cell comprising a working and a counter electrode at which the electrochemical assay is performed, comprising the steps of: (a) applying a pulsed voltage, Vw, to the working electrode while holding the voltage, Vc, of the counter electrode constant commencing at a time prior to the introduction of sample to the electrochemical test cell, said pulsed voltage having a pulse frequency; (b) monitoring the electrochemical test cell for the passage of current between the working and counter electrodes, said passage of current being in the form of current spikes having a frequency equal to the pulse frequency and being indicative of the addition of a sample to the electrochemical test cell, and (c) triggering the start of the electrochemical assay when a plurality of current spikes have been observed, and when said plurality is least a pre-determined fraction of a predetermined number of consecutive current spikes.