DNA sequencing is the process of determining the precise order of nucleotides within a DNA. It includes any method or technology that is used to determine the order of the four bases - adenine, guanine, cytosine, and thymine - in a strand of DNA.
Exonn provides comprehensive sequencing and bioinformatics services for healthcare, agriculture, aquaculture and environmental applications. Industry-leading customer service, high-quality results, and quick turnaround times using a broad array of innovative technologies make EXONN the partner of choice for researchers worldwide.
Exonn has strong and highly skilled employees, production facilities using state-of-the-art technology from all areas related to DNA applications, testing, analysis and research.
Exonn collaborates with many organizations and partners, providing highly reliable services for thousands of research projects, including several genome projects.
We provide a wide-range of genomic services
Many years of experience in DNA and RNA extraction in the scope of research as well as clinical studies enables us to offer DNA extraction based on different materials and samples prior to DNA sequencing in large scale, different volumes and of highest quality.
The use of 16S rRNA gene sequences to study bacterial phylogeny and taxonomy has been by far the most common housekeeping genetic marker used for a number of reasons. These reasons include (i) its presence in almost all bacteria, often existing as a multigene family, or operons; (ii) the function of the 16S rRNA gene over time has not changed, suggesting that random sequence changes are a more accurate measure of time (evolution); and (iii) the 16S rRNA gene (1,500 bp) is large enough for informatics purposes.
16S rRNA gene sequence informatics is to provide genus and species identification for isolates that do not suitable any recognized biochemical profiles, for strains generating only a "low likelihood" or "acceptable" identification according to commercial systems, or for taxa that are rarely associated with human infectious diseases. The cumulative results from a limited number of studies to date suggest that 16S rRNA gene sequencing provides genus identification in most cases (>90%) but less so with regard to species (65 to 83%), with from 1 to 14% of the isolates remaining unidentified after testing. Difficulties encountered in obtaining a genus and species identification include the recognition of novel taxa, too few sequences deposited in nucleotide databases, species sharing similar and/or identical 16S rRNA sequences, or nomenclature problems arising from multiple genomovars assigned to single species or complexes.
18S ribosomal RNA is a part of the ribosomal RNA. 18S rRNA is a component of the small eukaryotic ribosomal subunit (40S). 18S rRNA is the structural RNA for the small component of eukaryotic cytoplasmic ribosomes, and thus one of the basic components of all eukaryotic cells. Sequence data from these genes is widely used in molecular analysis to reconstruct the evolutionary history of organisms, especially in vertebrates, as its slow evolutionary rate makes it suitable to reconstruct ancient divergences. In general, rRNA gene sequences are easy to access due to highly conserved flanking regions allowing for the use of universal primers. Their repetitive arrangement within the genome provides excessive amounts of template DNA for PCR, even in the smallest organisms. The 18S gene is part of the ribosomal functional core and is exposed to similar selective forces in all living beings.
Internal transcribed spacer (ITS) refers to the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. In bacteria and archaea, ITS is located between the 16S and 23S rRNA genes. On the other hand, there are two ITS's in eukaryotes; ITS1 is located between 18S and 5.8S rRNA genes, while ITS2 is between 5.8S and 26S (in plants, or 28S in animals) rRNA genes. ITS1 corresponds to the ITS in bacteria and archaea, while ITS2 originated as an insertion that interrupted the ancestral 23S rRNA gene. The ITS1 and ITS2 regions are more variable than the adjacent rRNA gene sequences and thus promise a better separation of closely related species.
Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I is a protein that in humans is encoded by the MT-CO1 gene. Cytochrome c oxidase I is the main subunit of the cytochrome c oxidase complex. COX1 is one of three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Complex IV is the third and final enzyme of the electron transport chain of mitochondrial oxidative phosphorylation.
It is often used as a DNA barcode to identify animal species. MT-CO1 gene sequence is suitable for this role because its mutation rate is often fast enough to distinguish closely related species and because its sequence is conserved among conspecifics.
Targeted sequencing is a powerful way to increase the cost-effectiveness of variant discovery and detection. To generate a full view of relevant targets, you need complete and uniform coverage across regions of interest.