The invention relates to a perfusion manifold assembly that allows for perfusion of a microfluidic device, such as an organ on a chip microfluidic device comprising cells that mimic cells in an organ in the body, that is detachably linked with an assembly so that fluid enters ports of the microfluidic device from a fluid reservoir, optionally without tubing, at a controllable flow rate. The invention further relates to a drop-to-drop connection scheme for putting a microfluidic device in fluidic communication with a fluid source or another microfluidic device, including but not limited to, putting a microfluidic device in fluidic communication with the perfusion manifold assembly.