Abstract: A microfluidic apparatus and methods thereof. The Apparatus having a flat and thin substrate, the substrate including at least one microfluidic testing device, each device with: plurality of Stationary Nanoliter Droplet Array (SNDA) components; a common inlet port and a distribution manifold, configured to enable an introduction of a fluid into all the primary channels; plurality of individual inlet ports, each coupled to a different primary channel, configured to enable an individual introduction of a fluid into its associated primary channel; and one or more outlet ports and optionally a collecting manifold, configured to evacuate liquid and/or gas flowing out thereof.