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GSL - SAGE
Serial Analysis
of Gene Expression (An Alternative for Microarrays)
Serial Analysis of Gene Expression
(SAGE) is a sequence-based approach to the identification of differentially
expressed genes by comparative analysis. SAGE is a powerful tool, one of the
more comprehensive methods available for detailed analysis of large numbers of
cellular transcripts, leading to a profile of the expressed genes. SAGE provides
an accurate quantitative analysis of the relative levels of genes expressed in a
specimen. The ability to count many thousands of genes allows the detection of
genes that are expressed at very low levels in a high-throughput manner. A
three-step molecular approach, the SAGE process allows simultaneous analysis of
sequences derived from various cell populations or tissues.
 SAGE
is a well-recognized method of gene-expression profiling. The information
gathered from SAGE analysis enables a clear view of the genes associated with
normal, developmental, and disease states. Researchers require an efficient
means of accessing the sequence information contained in the concatamer of
transcript tags.
Recent advances in SAGE have provided
access to previously unexplored transcriptomes. Endothelial cells were isolated
from human tumors and analyzed by MicroSAGE, a modified SAGE method, and markers
specifically expressed in these cells were identified. LongSAGE was developed to
generate longer and more informative tags (21 bp), by which the human genome was
directly annotated. The results suggested that the number of genes expressed in
human might be significantly underestimated. In the search of the mediators of
apoptosis induced by p53 tumor suppressor gene, the transcriptional targets of
p53 identified by SAGE were verified and then investigated in somatic knockout
experiments. The combination of high-throughput SAGE analysis and gene targeting
in human cells has provided unique opportunities of studying function of genes
important in human biology and physiology.
Invitrogen Corporation has released
I-SAGE, the first pre-assembled kit for performing SAGE technology. This
all-inclusive kit provides sufficent pre-tested materials to generate up to six
SAGE libraries for subsequent sequencing.
For more detailed description of SAGE,
please visit: www.sagenet.org. | 
