Microwell array articles and methods of use

An article, comprising

• a microstructured layer with upper and lower major surfaces, comprising a plurality of optically-isolated microwells extending below the upper major surface;
• and
• an optically-transmissive flexible layer coupled to the lower major surface of the microstructured layer;
• wherein each microwell in the microstructured layer comprises an opening, an optically-transmissive bottom wall, and at least one side wall extending between the opening and the bottom wall;
• wherein a first thickness (t) is defined by a thickness of the bottom wall plus a thickness of the optically-transmissive flexible layer;
• wherein t is about 2 μm to about 55 μm;
• wherein a second thickness (T) is defined by a thickness of the microstructured layer plus the thickness of the optical transmissive layer, wherein T is less than or equal to about 156 μm;
• wherein the optically-transmissive flexible layer comprises a film comprising polyethylene terephthalate, polyethylene naphthalate, high density polyethylene, low density polyethylene, or linear low density polyethylene;
• wherein the optically-transmissive flexible layer further comprises an adhesive.