Gene Function Determination-An important aspect of functional genomics is to determine the function of specific genes/anonymous sequences. A powerful way to achieve this is to clone the gene, mutate it in vitro and to reintroduce the mutated gene into the host organism and analyse its effect.

Researchers have used high throughput strategies to mutate every gene in the genome, and collect the mutant strains to form genome wide mutant libraries. Such libraries have been developed in several model organisms like bacteria, yeast, plants, and mammals. This is sometimes dubbed as mutational genomics.