Figure 1.

nl-Reactors’ characteristics. nl-Reactors consist of a highly thermostable hydrogel and have a volume of 35 nl (diameter of 400 μm). The porosity of the capsule allows free diffusion of low molecular compounds whereas high-molecular-weight structures cannot penetrate. Embedded E. coli cells can therefore feed on externally provided nutrients and readily expand to colonies that remain immobilized within the nl-reactor. Similarly, larger DNA elements such as plasmids that were liberated from the colonies upon lysis or PCR products formed by thermocycling are also retained, while PCR reagents can continuously access and leave the nl-reactor.