| DNA microarrays allow the determination of the gene expression level of thousands of genes simultaneously. We review here a recently introduced physical model for hybridization (i.e. the binding of complementary DNA strands) in Affymetrix arrays. The model uses as inputs RNA/DNA hybridization free energies determined from experiments of duplex melting in solution. It also takes into account the hybridization between partially complementary RNA strands in solution. Microarray data follow rather well the microscopic model. This approach offers several advantages compared to traditional bioinformatics algorithms for the determination of gene expression levels. Correlation between hybridization free energies and signal intensities in hybridization experiments in spotted DNA microarrays are also briefly discussed. |
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