How do the cells stay in the well and not get washed away with the laminar flow created by the dual-nozzle action?

DropArray (or DA) plate has a unique patent-protected wall-less design.  The absence or minimal presence of a wall allows for laminar flow during the addition and aspiration of a liquid.  By nature of a laminar flow, the velocity of the flow reaches zero at the surface of a plate where cells are resting by gravity.  Such low velocity allows cells at the surface to remain where they are even if the number of cells is as small as one.   Yet, the bulk of existing liquid is replaced by an incoming liquid effectively rinsing the spot and cells.

The entire wash protocol has been optimized to combine the unique, patented features of wall-less plate as well as the flow rate and incubation time to obtain the greatest cell recovery.  Changing the flowrate is possible if desired.