Systems and methods for identifying light emitting droplets using an image sensor and lens system

A method for identifying light-emitting droplets, comprising:

• thermal cycling a sample vessel comprising a plurality of droplets, wherein the plurality of droplets comprises droplet PCR reagents and a nucleic-acid-binding fluorophore, and wherein at least a subset of the plurality of droplets comprise nucleic acid;
• and
• monitoring the sample vessel using a detector system, the detector system comprising an image sensor with an array of pixels, a structure associated with a surface of the image sensor, the structure extending a height away from the surface of the image sensor and defining a field of view for pixels within the array of pixels, and a lens system positioned within the field of view and defining an object space of the detector system and an image space for the image sensor, wherein the sample vessel positions a sample within the object space of the detector system so that light from a light emitting droplet in the sample is in the field of view of a plurality of pixels within the array of pixels;
• capturing a light intensity value at each photoactivated pixel of the image sensor receiving light from a real image of the sample vessel disposed in the image space;
• and
• identifying a number of light-emitting droplets based on the light intensity values.