update LabHead To discover new miRNA targets, we generated a C. elegans transgenic line expressing a functional, N-terminally tandem affinity purification (TAP)-tagged ALG-1 protein (TAP::ALG-1 strain) (see Methods for details).We next purified TAP::ALG-1 complexes from mixed-stage TAP::ALG-1 transgenic and wild-type animals (serving as a mock control) and hybridized the associated mRNAs to twocolor microarrays.