Microarrays mRNA expression

The ultimate goal of microarray-based expression analysis is to acquire a comprehension of the entire cellular process, in order to exploit and to standardize the multidi-menisional relations between genotype and phenotype. However, an increasingly important parameter, which has not yet been substantially taken into account, is the role of cellular translation. This means that mRNA expression data need to be correlated with the assortment of proteins actually present in the cell. One approach is based on the use of microarrays containing double-stranded DNA probes for the analysis of DNA-protein interaction and, thus, the detection and identification of DNA-binding proteins by means of fluorescence [130] or mass spectrometry analysis [131]. Moreover, substantial efforts are currently under way to develop protein, antibody, or even cell arrays, applicable to the cor-... 

This chapter will discuss various experimental approaches used to select the relevant species for conduct of toxicology studies for biopharmaceuticals, as well as highlight advances made in scientific approaches and technologies to facilitate this process. Methods discussed include the traditional immunohisto-chemistry and tissue cross-reactivity studies, flow cytometry, protein sequencing, and functional in vitro assays, as well as newer approaches such as utilization of microarray databases for genomic mRNA expression data and use of transcript profiling studies as an adjunct to functional assays, to understand similarity in pharmacological responsiveness between animals and humans. 

Key Words Adrenergic function gene expression gene profiling microarray mRNA receptor transcription. 

Nanomaterials can bind also to nucleic acids and, e.g., interfere with different methods used to assess changes in mRNA expression (PCR, real-time-PCR, and gene microarrays). In this case problems related to the presence of NMs are due to, e.g., decreased efficiency of RNA extraction from NP-exposed cells, lower quality of the extracted RNA, or altered mRNA stability [65],... 

Recent research efforts using microarray DNA chips (Biochemical Methods 18.1) have provided some of the details of the molecular mechanisms by which HIV disrupts the functioning of T-4 lymphocytes. By monitoring the mRNA expression of over 6000 genes simultaneously, researchers tracked the consequences of HIV infection. They observed that within 30 minutes of infection, the expression of about 500 cellular genes had been suppressed and 200 had been activated. Within hours, host cell mRNA had largely been... 

How do microarrays work Robotic technology is used to load thousands of samples of DNA or protein onto a microchip. Biological samples are then overlaid on the chip and the binding is evaluated through the use of fluorescence. In the case of a DNA chip, for example, the mRNA from a cell is labeled with a red fluorescent marker. When put on the chip, the location of the red dots tells which DNA sequences were matched by the mRNA. Another cell sample taken under different conditions may have its mRNA labeled with a green fluorescent marker. Gomparing where the red and green dots are then tells the researcher the differences in mRNA expression under the two circumstances. 

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