Summary: Genome-wide RNAi screening in Caenorhabditis elegans
Ravi S. Kamath and Julie Ahringer*
Wellcome Trust/Cancer Research UK Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
Accepted 7 February 2003
In Caenorhabditis elegans, introduction of double-stranded RNA (dsRNA) results in the specific inactivation of an endogenous
gene with corresponding sequence; this technique is known as RNA interference (RNAi). It has previously been shown that RNAi
can be performed by direct microinjection of dsRNA into adult hermaphrodite worms, by soaking worms in a solution of dsRNA,
or by feeding worms Escherichia coli expressing target-gene dsRNA. We have developed a simple optimized protocol exploiting this
third mode of dsRNA introduction, RNAi by feeding, which allows rapid and effective analysis of gene function in C. elegans.
Furthermore, we have constructed a library of bacterial strains corresponding to roughly 86% of the estimated 19,000 predicted
genes in C. elegans, and we have used it to perform genome-wide analyses of gene function. This library is publicly available, re-
usable resource allowing for rapid large-scale RNAi experiments. We have used this library to perform genome-wide analyses of
gene function in C. elegans. Here, we describe the protocols used for bacterial library construction and for high-throughput
screening in C. elegans using RNAi by feeding.
Ó 2003 Elsevier Science (USA). All rights reserved.
Because of its anatomic and genetic simplicity, the
nematode Caenorhabditis elegans has become an inten-
sively studied simple animal model system. Further-