| Microarray technology - allowing the massive parallel profiling of gene expression in a single hybridisation experiment - has gained acceptance as a powerful molecular genetic tool for biomedical research. Historically, gene analysis was performed through immobilisation of DNA probes on supports such as nylon membrane or nitrocellulose, allowing their hybridisation to radioactivity labelled complementary sequences. However, the increasing sequence data derived from the genome projects has prompted the automation of array production and demanded more practical support for large-scale genome studies.A number of different substrates have been tested as solid supports for nucleic acid immobilisation. For several reasons, glass became the favourite choice within the microarray technology because its non-porosity liquid cannot penetrate the surface. This speeds up the kinetics of hybridisation by keeping the hybridisation volume small. It is a durable material and has great chemical resistance so that robust chemistries can be used for a covalent binding of oligonucleotides to the surface. Furthermore, glass has low intrinsic fluorescence properties which improves the signal to noise ratio when high intensity lasers are focused on the surface. |
