Microarrays can quantitatively measure the expression of thousands of genes simultaneously but they are also powerful tools to examine the expression of specific genes in different tissues and cell types. They complement other methods used to detect gene expression at the transcript level, including Northern blotting and RT-PCR. This study uses oligonucleotide microarray expression profiling to compare maize beta-tubulin (tub) gene expression at the transcript level in different tissues and during various stages of development and adds to what is known about maize beta-tubulin expression. In maize, at least nine beta-tubulin genes are expressed. The presence of multiple tub genes suggests that some could have evolved to provide fine control of expression or even have distinct biological or physiological properties in the plant. This is supported by the differential expression at the transcript level of the maize beta-tubulins in different tissues during development. The following work has added evidence of maize beta-tubulin gene differential expression and regulation. Based oil microarray data, some beta-tubulins exhibit statistically significant differences in transcript abundance in 11-day old seedling shoots, immature ears, 19-DAP embryos, 13-DAP endosperm and 19-DAP endosperm. There are also different expression patterns for many of the tubulin genes within the tissues Studied. As the plant develops it may use beta-tubulins in different amounts in specific tissues, and these tubulins may even interact differently with other proteins present at these developmental stages. In immature ears, tub1 and tub2 have higher transcript abundances. Comparisons of expression patterns indicate that tub3 and tub4 have very similar expression patterns, which may be a result of similar transcriptional regulation. The highest transcript abundance of these two genes occurs in developing seedling shoots. tub3 and tub4 transcripts have also been detected for the first time in maize endosperm. This chapter describes a variety of methods for array analysis of tubulin gene expression as well as important considerations before taking oil this type of work.