DNA-Microarray/DNA chip

The DNA chip method, biochip or DNA microarray makes it possible to analyze the level of expression of genes in a cell at given moment and in a given state. This technique is based on the single-strand DNA property of reforming a double helix when it is in the presence of a complementary single-strand. In concrete terms, it consists in extracting the mRNA from the cells of interest. After amplification of these mRNA in order to obtain a sufficient amount of material for the experiment, these are transformed into complementary DNA (cDNA) and labeled. This cDNA is then placed in the presence of single-strand DNA chosen according to the genes tested and fixed to a glass, plastic or silicon surface. Thanks to the labeling, one can observe which strands of DNA and cDNA have assembled to reform a double helix.

Flash animation of the microarray methodology