NA Sequencing

DNA double helix structure was first explained by Watson and Crick. The first natural polynucleotide DNA sequence was announced in 1953. Due to the development of many sequencing techniques, the entire human genome was sequenced in 2003 as a result of the Human Genome Project. The goal of the Genome Project, a large-scale scientific initiative, is to investigate and evaluate the chemical sequence of the 50 000-100 000 genes that make up the human genome or the entire collection of all genetic material. The separation and examination of the genetic code included in DNA provide the basis for this huge project. Considering the size of the human genome, scientists must have developed new techniques for DNA analysis that can quickly, cheaply, and reliably analyse massive amounts of data. DNA sequencing methods requiring large- scale application have driven technology to both enhance capacity and decrease instrument size. This demand has prompted the creation of automated equipment that speeds up and lowers the cost of biochemical processes connected to sequencing, enhances the analysis of these reactions, and makes it simpler to enter the resulting data into databases (Behjati and Tarpey 2013). It was not possible for scientists at the time to sequence nearly a full gene because they could only sequence a few base pairs per year. Despite difficulties in the sequencing process, the first complete genome sequencing was completed with an explosion of RNA and DNA sequencing that improved procedures and provided new data. This eventually gave rise to the Maxam and Gilbert chemical degradation DNA sequencing method, which physically separates terminally tagged DNA fragments by electrophoresis and chemically cleaves specific bases of those pieces (Collings et al., 1998). Maxam-Gilbert, called the first-generation sequencing method, is based on chemical fragmentation of DNA and imaging with electrophoresis (Dogan et al., 2017). Later, a new technique with higher simplicity, reliability, and a lower hazardous level was developed. It was simply called the Sanger sequencing method. Automated Sanger DNA sequencing with fluorescent dye labels predominated when the Human Genome Project was finished in 2003 (Behjati and Tarpey 2013). Sanger technique, which uses fewer chemicals and is less harmful, is still regarded as the gold standard today (Zhang et al., 2021). DNA sequencing refers to methods for determining the order of the nucleotide bases adenine, guanine, cytosine, and thymine in a molecule of DNA. The first DNA sequence was obtained by academic researchers, using laboratories methods based on 2- dimensional chromatography in the early 1970s. By the development of dye based sequencing method with automated analysis, DNA sequencing has become easier and faster.