Options available for labelling nucleic acid samples in DNA microarray-based detection methods.

DNA microarrays are considered by many researchers to be the platform of choice for the high-throughput analysis of nucleic acids. Since the past two decades, they have been used constantly as powerful tools in differential gene expression, SNP genotyping, DNA sequencing, gene discovery, disease diagnostic and pathways reconstruction. Several methods have been developed to enable samples of limited amounts of RNA to be quantified. Here we evaluate classical and up-to-date assays made available for labelling those samples. This review also sheds light on the recently developed strategies that ensure high sensitivity such as sample and signal amplification, quantum dot, surface plasmom resonance, nanoparticles and cationinc polythiophenes.