Others have used microarrays or alternative methods to map expression in specific tissues or cell types [ 3- 7].
This led directly to today's emerging approach, gene expression profiling, by which the expression levels of thousands of genes throughout the genome are measured by DNA microarrays or alternative techniques.
DNA methylation is likely to be one of many molecular mechanisms involved in caste development, but these mechanisms as a whole will lead to changes in gene expression, detectable using microarray techniques, or alternative splice isoforms detectable using transcriptomics.
Such transcriptomic approaches have been undertaken for different plant-oomycete interactions either by microarray analysis or alternative, open-architecture technologies, thus revealing novel information about pathogen genes [ 24- 29].
The studies we know of are concerned with microarray expression profiles or alternative methods for estimating the amount of host material or cell types in the samples.
Nevertheless, multiple platforms for quantifying mature miRNAs exist, which are most commonly based on either quantitative real-time PCR (qRT-PCR) or microarrays, although alternatives exist [ 11].
For biological systems that lack the sequence information necessary for development of microarrays, several alternative technologies based on cDNA fragment analysis or cDNA sequencing have been developed.
Microarrays from alternative manufacturers with shorter probes (e.g. 25 or 30 mer) might not have detected similar deletions because they have been shown to be less sensitive than longer probes [ 26, 27].
Besides microarray iSPR, several alternative multiplex systems have been developed to profile biomolecular markers in RA.
Therefore, it is important to validate results obtained with microarray, with an alternative approach such as RT-qPCR.
