Advances in spotted microarray resources for expression profiling

Abstract

The new millennium has ushered in a new era in human biology. The elucidation of the human genome sequence, together with those of model organisms, provides us with an unprecedented insight into the makeup of our genetic blueprint. The challenge now is to figure out how all the constituent pieces fit together to form the whole picture, and the consequences of what happens when the process goes awry. One experimental tool that has the potential to provide enormous insights into this complex process is expression profiling using microarrays. The past few years have seen a considerable growth in the availability and use of microarrays. Fuelled in part by the many genome projects currently underway, there has been a large increase in the number of organisms for which microarray reagents are available from both commercial and academic sources. In addition to the increasing number of genome-wide probe sets that are available, a significant amount of attention has been focussed on generating more targeted probe sets that focus in on specific pathways or biological processes. Finally, the microarray field is starting to see a shift away from the use of cDNAs or polymerase chain reaction (PCR) products as probes towards the use of 50-70mer oligonucleotide probes with all of the potential advantages that they offer. The aim of this review is to provide an overview of what is currently available in terms of spotted microarray reagents both with respect to pre-made arrays and to probe sets available for arraying.