Serial analysis of gene expression

The serial analysis of gene expression ( SAGE, of Engl. Serial Analysis of Gene Expression) is an effective method for the identification of short cDNA fragments, so-called tags, which transcriptase mRNA molecules were obtained by means of the enzyme reverse. The method was developed in 1995 by Victor Velculescu.

While the original SAGE method only spawned tags with 10-14 bp, resulting from the current variant Super Sage tags with a length of 26-28 bp. This allows a much better association with known gene sequences allowed the design of specific primers for RACE -PCR, for example, and opens up new possibilities of analysis, such as the simultaneous analysis of several organisms. Due to the longer tags Super Sage is also recommended for the analysis of organisms with unknown genomes and the discovery of new genes and transcript variants.

With SAGE and its variants, the transcriptome of a cell, a tissue or an organ to any development or stage of disease can be comprehensively analyzed.

SAGE and its variants enable the analysis of a very large amount of genes. Furthermore, the number of gene-specific mRNA molecules can be relatively well determined; Sage is thus a quantifiable method. With respect to the microarray method, which can detect as a closed system, only known and gespottete genes SAGE provides as open system has the advantage that even unknown gene, or genes, of which was not expected to find are to be detected and evaluated.