The Oligonucleotide/DNA Synthesis Facility is a shared resource that will serve two purposes for investigators in the University of Chicago Cancer Research Center: (1) to provide high-quality custom-made oligonucleotides rapidly and inexpensively and (2) to perform single- or double-stranded sequencing of cDNA and genomic DNA segments isolated by standard cloning or polymerase chain reaction (PCR) amplification techniques. Oligonucleotides will be used as primers for both traditional and PCR gene cloning applications, for mutagenesis studies and for studies of protein/DNA interactions. The sequencing service will facilitate the characterization of various transcribed genes under investigation as well as nontranscribed regions of DNA that are involved in the regulation of gene expression. the programs and projects supported by this Facility represent a diverse, multidisciplinary approach to obtaining an improved understanding of cancer biology, genetics, immunology, chromosomal abnormalities and therapeutic modalities. Because the demand for oligonucleotides and DNA sequencing among the faculty is increasing exponentially, both services will greatly enhance the productivity and efficiency of the Cancer Center. It is anticipated that a facility operated by two full-time technicians and equipped with three nucleotide synthesizers and an automated DNA sequencer will have a major impact on the ability of investigators to rapidly isolate and characterize new, known or mutant genes of interest. Because the projects utilizing the core will have common needs, effective operation and use of the facility will enable maximum progress at minimum cost while ensuring quality control.