Copy Number Determination: Introduction

The yeast transcriptome has been measured by HDA (1) and SAGE technology (2). Both methods have been considered to allow a better measurement of the absolute copy numbers of mRNA transcripts, while DNA microarrays, on the other hand, were better suited for assessing the relative abundance of mRNA transcripts. Here, we report a simpler and more economical approach to measure the yeast transcriptome using DNA microarrays. Compared to the standard microarray experiments, in which relative change in expression level of a given mRNA transcript was measured as a ratio to a common mRNA reference pool, we used the yeast genomic DNA (with less complexity and a single copy present for most the genes) as a convenient and suitable normalized reference to measure the absolute abundance of each mRNA transcript.

References:

1. F. C. Holstege et al., Cell 95, 717-28. (1998).
2. V. E. Velculescu et al., Cell 88, 243-51. (1997).