DNA chips, also called expression arrays, are used by the GENEX Laboratory to screen the entire human genome (60,000 gene sequences).

RNAs extracted from cells or tissues are transformed into complementary DNA (cDNA) by the reverse transcription technique (RT) and labeled with a fluorochrome.
After analysis by a very high resolution scanner the fluorescence intensity will be quantified. The comparison of the intensities between a treated sample versus a control sample will allow us to highlight whether the expression of a gene is activated or inhibited. When a gene is activated in response to treatment, it synthesizes a messenger named mRNA that will be responsible for protein synthesis.

The interest of large-scale screening?
Genes/proteins work together and one gene alone can not account for the activation of a process. Claiming an allegation requires identifying a "functional network" in which several genes will interact directly or indirectly. The function of these genes may have never been documented in skin tissue and the involvement of these genes, highlighting the specificity of the active ingredient, is a source of innovation.

miRNA chips
From total RNAs, it is possible to evaluate human miRNome (2300 miRNAs - 23 to 25 nucleotides) and to quantify them via the use of miRNA chips. This quantification makes it possible to evaluate the modulation of miRNA expression present in a treated sample versus the control sample and consequently to identify the impact of an active on their synthesis. (See Newsletter # 2 for more information).

Epigenetics plays a key role in the regulation of gene expression and DNA methylation is involved in various cellular processes, it is a particular marker of skin aging. Low methylation promotes mRNA transcription, conversely strong methylation inhibits it.
Genex laboratory proposes to evaluate the level of methylation of the genes (methylome) using MethEPIC array 850k and to correlate them with the expression of mRNA via qPCR.