Genome-wide detection of novel non-coding RNAs in S. cerevisiae by modulating an RNase P pathway through the depletion of a component RPP1. Nearly 400,000 36-mer oligonucleotide probes tiling the entire yeast genome including the mitochondrial chromosome with an average gap of 10 bases between two consecutive probes were synthesized on glass slides using a mask-less array synthesizer. RNA samples for hybridizing to the arrays were extracted from a conditional lethal allele of S. cerevisiae created by placing the RPP1 gene under control of GAL10 promoter. It allowed the expression of RPP1 in galactose-containing culture medium but suppressed its expression in glucose-containing medium. A wild-type isogenic strain was used as a control. Both strains were initially grown in galactose-containing medium and subsequently transferred and resuspended into glucose-containing medium. Eight arrays were hybridized with RNA extracted from the Rpp1-depleted cells at 0 4 7 12 16 21 30h and the control cell at 30h after initial transfer to glucose-containing medium.