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High Throughput Sequencing for Gene Expression

Despite the fact that the human genome has around 30,000 genes, our cells only express a handful of them for daily functions. For example, the difference between a liver cell and a heart cell are determined by the gene expression. According to Science Daily, their gene expression could mean the difference between health and disease.

Because of previous imaging approaches, studying underlying disorders has been a limited field. The University of Michigan Medical School, led by Jun Hee Lee, Ph. D, recently developed a new technique that uses high throughput sequencing instead of a microscope. Other methods that have developed, such as microprinting, microbeads, and/or microfluidic devices have their limitations.” At that resolution you can’t really see the level of detail needed to diagnose diseases.” Lee said. This enables the researchers to obtain an ultra-high resolution image of gene expression from a tissue slide.

Seq-Scope technology allows researchers to see every gene expressed, including single cells and the structures within those cells. Items are visible at 0.6 micrometres, or 66 times the size of a human hair.

Image is Courtesy of Azo Life Sciences

Life Sciences News says the team demonstrated the technique's effectiveness by identifying dying liver cells, their surrounding inflamed immune cells, and liver cells with altered gene expression in normal diseased liver cells. When the technology was used, it was able to show known pathological features as well as genes that are regulated in a previously unknown way.

Lee explains that their method and microdevice involved overlaying the tissue sample and sequentially sequencing everything within it with a barcode with spatial coordinates. Instead of the traditional strategy of staining a tissue sample and examining it under a microscope, he and his colleagues developed this method to diagnose.

Each barcode is constructed from a nucleotide sequence that includes cytosine, guanine, thymine, and adenine patterns. A computer can find every gene in a tissue sample and then create a "Google-like" database of all messenger RNAs transcribed from the genome. Jun Hee Lee state that the technology “combined ieht other single cell RNA sequencing techniques, could accelerate scientific discoveries, and might lead to a new paradigm in molecular diagnosis.”

Article Author: Idil Gure

Article Editors: Edie Whittington, Sherilyn Wen