ABSTRACT
Transcriptomics projects utilizing high throughput gene expression technology provide invaluable landscape information for biological systems. The most common forms of high throughput gene expression used to date are deoxyribonucleic acids microarray based technologies. The ever-decreasing cost of high-throughput sequencing technologies has rendered exploratory gene detection methods amenable to a throughput compatible with a quantitative assessment of transcript expression levels. Cap Analysis of Gene Expression (CAGE) tag sequencing is a very new approach to measure gene expression. For the comparison between CAGE expression data and Illumina® microarray data, quantile normalization was used for the microarray data. Quantitative Reverse-Transcribed Polymerase Chain Reaction gives us an absolute expression level of ribonucleic acids (RNA), CAGE gives us a relative expression level of tag, and microarrays gives us the relative expression of RNA in one condition compared to its expression in another condition. When comparing gene expression measurements between platforms, additional normalization steps may be needed for consistency.
