Assay apparatuses, methods and reagents including devices and methods for reducing crosstalk between CCD measurements

A method of reducing crosstalk between measurements of a plurality of analytes in an assay plate performed by a CCD camera, the method comprising:

• measuring the plurality of analytes with the CCD camera, the CCD camera including a CCD, an analog front end circuit, and an analog to digital circuit and being coupled to a focusing system and a plate carriage system configured to locate the assay plate to facilitate measurement of the plurality of analytes;
• receiving, via the analog front end circuit, a readout signal from the serial register of the CCD, wherein receiving the readout signal includes:
• transferring the readout signal from the serial register to the analog to digital circuit to generate a first image data point,
• resetting fully, via a reference level clamp circuit having a time constant, a reference level of the analog front end circuit,
• transferring the readout signal from the serial register to the analog to digital circuit to generate a second image data point,
• wherein the time constant is selected so as to reduce crosstalk between a first measurement of a first one of the plurality of analytes and a second measurement of a second one of the plurality of analytes.