Portable high gain fluorescence detection system

An apparatus for performing a fluorescence assay on a sample contained in a detection chamber of a microassay cartridge, the apparatus comprising:

• a) a housing configured for receiving the microassay cartridge, the housing comprising a host controller with clock, memory and firmware, and a scanning detector head, wherein the scanning detector head is configured to move in a series of spatially resolved steps over the detection chamber according to instructions executed by the host controller, the scanning detector head comprising:
• i) one or more optical channels, each optical channel having an excitation light source, an objective lens for directing the excitation light onto the sample and for receiving fluorescence emissions therefrom, an emissions sensor for detecting the fluorescence emissions, and an amplifier circuit operatively connected to the emissions sensor, wherein the amplifier circuit is enabled to amplify a voltage from the sensor, thereby generating an amplified voltage signal output;
• ii) an embedded microprocessor with clock, memory, and firmware for performing a scan of the microassay cartridge while the scanning detector head is moving in the series of steps under control of the host controller, the embedded microprocessor having an electronic input for receiving the amplifier output, wherein the embedded microprocessor is enabled to digitally process the amplifier voltage signal output at each step of the scan across the detection chamber;
• b) further wherein the embedded microprocessor generates a digital output comprising digitally processed data collected during the scan and conveys the digital output to the host controller;
• and
• c) further wherein the embedded microprocessor is configured to compare the amplified voltage signal output with a threshold value and score the signal as a digital one if greater than the threshold value and as a digital zero if less than the threshold value for each step in the scan, and the digital output is a string of single-bit digital scores for each step in the scan.