Critically evaluate the current methods of high-throughput expression Essay

Critically evaluate the current methods of high-throughput expression profiling in normal and disease states - Essay Example These studies have provided information that was challenging to find, making it easy to detect diseases very early and applying the necessary intervention and treatment procedures on time reducing rates of morbidity and mortality. The first step n the quest to understand the cell function would be understanding gene expression of the various cells of the body. In that case, it would be easier to determine when cells are not expressed as expected. Scientists and researchers point out that gene expression anomalies mostly involve the Messenger RNA (mRNA). DNA Microarrays are used to measure the expression of cells within a predefined mRNA. Different cells are expected to be expressed in a certain way in the mRNA. Changes in expression include over-expression or under-expression. For example, scientists have confirmed that breast cancer cells express more mRNA for the membrane receptor (Suter, Babiss and Wheeldon, 2004). DNA methylation which is important in the normal DNA function and gene expression can be used to detect the changes in the DNA leading to abnormal expression and disease. Hyper-methylation and hypo-methylation have been associated with significant changes in some cells. Cells of the breast canter are usually hyper-methylated leading to neuroblastoma risks and response to the tamoxifen (Widschwendter et al., 2004; Martens et al., 2005). Hyper methylation has also been associated with Leukemia, Ovarian cancer and colorectal cancer (Baylin, 2005). The varying magnitudes of methylation in the cells are associated with different stages of cancer development, and DNA methylation technique can be used to determine the exact stage (Costello et al, 2000). Use of DNA and genes is made very easy by the availability of data of all genomes in the human body. Researchers can access this information anytime from the human genome project databases. Use of gene expression is a three step process that involves class comparison, class prediction and analyzing the va rious genes sets profiles. All this information is presented on pre-processed images which are normalized to make sense (Tarca et al, 2006). DNA microarrays are limiting in that they can only be used for know cells. This limitation necessitated the introduction of RNA sequencing in which unknown genes expression can be studied (Cloonan et al, 2008). Single cell sequencing in which the different types of healthy and cancerous cells can be sequenced individually has improved the effectiveness of DNA micro array studies. All the cells that are studies are amplified using the polymerase chain reaction (PCR) to achieve better and accurate results (Wang and Bodovitz, 2010). Micro arrays can be used to analyze thousands of cells from different patients at once making it time efficient unlike the previous methods of analysis. The technique provides information on DNA, RNA and the proteins simultaneously. Throughput profiling can also be done at the product level of gene expression; proteins in this case are studied for any anomalies. Mass Spectrometry is used to determine the differences between normal cells and diseased cells for example cancer cells (Aebersold and Mann, 2003). This procedure has proved very important in detecting prostate cancer in early stages, which has been a major challenge. In this case, the fluids, peptides and serum from the prostate are examined using the SELDI mass spectrometer which uses affinity capture. Some cells are