I discuss and compare several micro-array technologies for
performing sequencing, SNP (single nucleotide polymorphism)
identification, and expression analysis, including the 5' nuclease
assay proposed by Perkin-Elmer Corp. and the Hyseq HyChip(TM)
ligase assay. The speed and sensitivity of each format is estimated
using simple models of chemical kinetics. A rough appraisal
of assay costs is also provided.