Targets of Analysis by DNA microarrays
A DNA microarray can detect various nucleic acid molecules depending on the preparation method of the nucleic acid target. This property enables the analysis of many vital processes. The first DNA microarrays developed were able to comprehensively detect mRNA expression levels, and these DNA microarrays are still readily available today. Studying mRNA enables the selection of genes specifically expressed in a certain environment, and the selection of disease-related genes. In addition, the states of samples can be determined using gene selected for tests and diagnosis. These states involve diagnosis of cancer or non-cancer and monitoring of physiological conditions.
In recent years, applications have been developed for nucleic acid analysis other than of mRNA. The following table summarizes items that can be examined using DNA microarrays.
| Targets of Analysis by DNA microarrays | Summary |
|---|---|
| Amount of transcription product (mRNA) | So-called “gene expression analysis” The amount of transcription product is measured, and a profile of mRNA in a sample is obtained. |
| miRNA level | An expression level of a type of functional RNA, miRNA, is examined. miRNA is thought to be involved in the inhibition of transcription and translation. miRNA can be analyzed simultaneously with mRNA. |
| SNPs (single nucleotide polymorphisms) |
A SNP is a polymorphism in one base on a chromosome and is thought to cause differences in traits among individuals. |
| Copy numbers of genomic DNA regions | In cells which have become cancerous, chromosomal mutations such as transposition, translocation, and duplication have occurred. The regions with mutations can be detected by comparison with normal cells. |
| Binding sequences of DNA bound proteins | Factors such as transcription factors are known to bind to genomic DNA and inhibit cellular functions. ChIP-on-Chip is a method that examines in which region of genomic DNA such factors are bound. |
| Base sequence | Sequencing by hybridization: DNA base sequences can be examined by hybridization reaction. |
* Target of analysis of 3D-Gene® is the amount of mRNA or miRNA.