Genome sequence information in combination with new technologies has allowed researchers to approach genetic
problems in new ways. High-density oligonucleotide arrays were used to probe the genome content of the yeast
Saccharomyces cerevisiae. We show that these arrays, containing oligonucleotides complementary to the sequenced strain
of S. cerevisiae, can be used to identify open reading frames that are missing or present in higher or lower copy number
in related isolates of S. cerevisiae. We apply this method to the characterization of the genome of a strain derived from
a clinical isolate of S. cerevisiae. Our results show that the telomeres are the regions with the most variability between the
two strains.