How were the C. elegans RNAi feeders constructed?

The inserts from the C. elegans ORF clones were moved into the feeding vector. A brief description of the protocol is in the following reference: Jean-François Rual., et al (2004) "Towards Improving Caenorhabditis elegans Phenome Mapping With an ORFeome-Based RNAi Library" Genome Research 14:10b 2162-2168.