BioWorld International Correspondent

PARIS - Genome Express unveiled a new technology that it said will speed up the discovery of genes of therapeutic interest and which it is making available to third parties on a fee-for-service basis.

Called Discriminative Analysis of Clone Signatures (DACS), it is based on EST (expressed sequence tag) sequencing, but is a simplified version that is less costly and equally valuable, Genome Express said. DACS entails the marking of only one of the four bases that make up DNA - A, C, G and T - followed by a multiplexed sequencing that enables 1,536 samples to be analyzed per run. The signals obtained from the sequencing make it possible to distinguish between identical clones and different clones due to a patented signal-processing technique that highlights gene expression.

The first application of the technology, GE-DACS (Gene Expression DACS), is designed to eliminate a bottleneck in the process of discovering genes expressed in a cell or tissue. Genome Express said that, relative to existing methods, it cuts both the cost and the time taken to generate results and to extract the information required for gene expression analysis. The method yields "ready to spot" collections of PCR products on an analytical support, such as microarrays, which the company said have become an essential tool for studying complex diseases such as diabetes, cancer and obesity.

Genome Express added that, compared with other techniques such as SAGE1 (Serial Analysis of Gene Expression), DACS not only speeds up the discovery process but also makes it possible to carry out gene expression analysis in the absence of data about the organism concerned (its genomic sequence or EST2 sequences).

The company also pointed out that, since it is based on the generation of clones of complementary DNA, the technology enables the original biological material to be kept intact and establishes a link with the information generated for each clone. Hence, if researchers suspect that a gene is involved in a particular disease, they can use the original biological material for carrying out an in-depth analysis.

Moreover, the simplicity of the process means that experiments can be fully and accurately reproduced, which Genome Express said is essential for the analysis of differential gene expression, comparing expression in a normal cell with that in a cancerous cell, for instance.

The company's technical director, Jean-François Mouret, told BioWorld International that the technology could not simply be sold to third parties in kit form because it required a certain know-how, a molecular biology laboratory and a lot of biological equipment. Customers would thus have to send samples to Genome Express for analysis. He added that the company has invested heavily in the technology and that, provided potential customers are convinced of its merits, DACS should contribute significantly to its revenues in 2003, 2004 and beyond.