In vitro evolution in microfluidic systems

A method for producing an encapsulated gene product, comprising the steps of:

• (a) providing within a first microcapsule within a microfluidic channel a first genetic element encoding a first gene product;
• (b) providing conditions within the first microcapsule suitable for the expression of the first genetic element to form its first gene product;
• (c) introducing at least one of a first microbead to the first microcapsule, wherein the first microbead is either encapsulated within the first microcapsule prior to the expression of the first genetic element or is encapsulated within the first microcapsule subsequent to the expression of the first genetic element;
• and
• (d) complexing the first gene product with at least one of the plurality of first microbeads.