Patent ID: 8431389

Claim:
An apparatus comprising a scanning detector head having two or more optical channels for detecting at least one fluorescence signal in a liquid sample, the apparatus comprising a chassis having a docking port for receiving a disposable microfluidic cartridge therein, the microfluidic cartridge comprising a detection chamber, the detection chamber having a first optical window and a second optical window oppositely disposed thereon; wherein, a) the second optical window is a thermo-optical window formed of a compliant thermo-optical film; b) the scanning detector head comprises a drive train configured to guidedly scan across the detection chamber, the chassis further having a clamping mechanism for clamping the microfluidic cartridge in the docking port and for urging the compliant thermo-optical film of the microfluidic cartridge into thermoconductive contact with a heating element affixed to the chassis; c) each optical channel comprises an objective lens, a light source with source lens for transitioning excitation light through the objective lens and into the detection chamber, a dichroic beamsplitter and an emission detection sensor with emission sensor lens; and d) the heating element is surfaced with a mirror face positioned to thermo-optically contact the second optical window; and the heating element with mirror face is configured for reflecting excitation and emission light incident thereon back into the objective lens, while also controlling or adjusting the temperature in the detection chamber; and wherein for each of the optical channels, the light source is positioned at a first distance from the source tens, the native focal point of the source lens is at second distance from the source lens, wherein the first distance is not the same as the second distance, such that the focal point of the excitation light through the objective lens is at a third distance from the objective lens, the native focal point of the objective lens is at a fourth distance from the objective lens and third distance is not equal to the fourth distance.