Array platforms CDNA arrays(spotted arrays Probes are PCR products from cDNA libraries or clone collections May be printed on glass slides(e.g, P. Brown lab, Stanford), OR May be printed on nylon membranes(e.g, Millennium Spots are 100-300 um in size and about the same distance apart 30,000 CDNAs can be fit onto the surface of a microscope slide Oligonucleotide arrays 20-25 mers synthesized onto silicon wafers in situ or printed onto glass slides by: photolithography(Affymetrix)or ink-jet printing(Rosetta/Agilent Presynthesized oligos can also be printed onto glass slides Other technologies (e.g, bead arrays attached to optical fibersArray Platforms • cDNA arrays (spotted arrays) – Probes are PCR products from cDNA libraries or clone collections – May be printed on glass slides (e.g., P. Brown lab, Stanford), OR – May be printed on nylon membranes (e.g., Millennium) – Spots are 100-300 µm in size and about the same distance apart – ~30,000 cDNAs can be fit onto the surface of a microscope slide • Oligonucleotide arrays – 20-25 mers synthesized onto silicon wafers in situ or printed onto glass slides by: by: photolithography (Affymetrix) or ink-jet printing (Rosetta/Agilent) – Presynthesized oligos can also be printed onto glass slides • Other technologies (e.g., bead arrays attached to optical fibers)