Microinjection of Synthetic Peptides Into Caenorhabditis elegans

The genome of the nematode Caenorhabditis elegans encodes at least 160 predicted peptide precursor genes that can generate over 300 bioactive peptides, the functions of most of which remain unknown. Phenotypes resulting from deletion or transgenic expression of peptide genes are readily assayed, but genetic dissection of individual peptide activities is often confounded when a single gene encodes multiple peptides or when distinct peptides act redundantly. Here, we describe a protocol for direct microinjection of chemically synthesized peptides into individual worms. This approach permits investigation of the effects of an individual peptide while providing precise temporal control over peptide delivery. Key features • Direct injection of chemically synthesized peptides into nematodes. • In vivo effects can be analyzed within one day after peptide delivery. • Full control over peptides, chemical modifications, genetic background, and timing of delivery. • The approach may be adaptable to non-peptide compounds.