Patent ID: 7948015

Claim:
An integrated circuit chip for determining byproducts of a plurality of extension reactions, the integrated circuit chip comprising: a sensor array of at least 10 5 sensors formed in a semiconductor substrate, each sensor of the array comprising a field-effect transistor having a threshold voltage and a floating gate with an analyte-sensitive passivation layer, the threshold voltage depending substantially on the analyte-sensitive passivation layer and trapped charge at the floating gate wherein the field-effect transistor is configured to provide at least one output signal dependent on the threshold voltage, and wherein the trapped charge of each floating gate is such that the threshold voltage is substantially the same for each sensor in response to the same amount of extension reaction byproduct proximate thereto; a plurality of microwells disposed on the semiconductor substrate, each microwell capable of containing a separate extension reaction and being disposed on at least one sensor; and control circuitry in the semiconductor substrate coupled to the sensor array to receive samples of the output signals from said field effect transistors at a rate of at least twenty frames per second so that the amounts of extension reaction byproducts are determined in each microwell by the output signal produced therefrom.