The disclosed embodiments generally relate to a method and system to synthesize a target molecule within a droplet. In an exemplary embodiment, a first microfluidic device configured to contact a polynucleotide-containing component from a sample with lysis reagents to form a first droplet. The lysis reagents include an enzyme having protease activity. The first droplet is encapsulated with an immiscible carrier fluid. A collection reservoir is provided to receive and incubate the first droplet for a first duration of time. The first duration of time is sufficient to inactivate the enzyme of the lysis reagent. A second microfluidic device is provided to receive the first droplet and add nucleic acid synthesis reagent to thereby form a second nucleic acid synthesis droplet in the immiscible carrier fluid. Finally, a reaction chamber is provided to synthesize the target polynucleotide within the second nucleic acid synthesis droplet.