<p>The present disclosure teaches an apparatus and a method for providing one or more substance liquids to a microfluidic channel network (30). The microfluidic apparatus includes valves for switching the one or more substance liquids to a microfluidic channel network (30). The apparatus can be used to generate a sequence of the one or more substance liquids as individual droplets in an immiscible separation liquid wherein individual ones of the sequence of droplets are located between the separation liquid.</p>
