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It is the first step of viral replication. Some viruses attach to the cell membrane of the host cell and inject its DNA or RNA into the host to initiate infection. Attachment to a host cell is often achieved by a virus attachment protein that extends from the protein shell (), of a virus.
Once a one-step RT-PCR kit with a mix of reverse transcriptase, Taq DNA polymerase, and a proofreading polymerase is selected and all necessary materials and equipment are obtained a reaction mix is to be prepared. The reaction mix includes dNTPs, primers, template RNA, necessary enzymes, and a buffer solution.
Viruses were known to be composed of a protein shell and DNA, so they chose to uniquely label each with a different elemental isotope. This allowed each to be observed and analyzed separately. Since phosphorus is contained in DNA but not amino acids, radioactive phosphorus-32 was used to label the DNA contained in the T2 phage. Radioactive ...
CryoEM of nucleic acid has been done on ribosomes, [7] viral RNA, [8] and single-stranded RNA structures within viruses. [ 9 ] [ 10 ] These studies have resolved structural features at different resolutions from the nucleobase level (2-3 angstroms) up to tertiary structure motifs (greater than a nanometer).
This allows the virus sample to be grown into larger quantities and allows a larger number of tests to be run on them. This is particularly important for samples that contain new or rare viruses for which diagnostic tests are not yet developed. [citation needed] Many viruses can be grown in cell culture in the lab.
The virus's nucleic acid uses the host cell's metabolic machinery to make large amounts of viral components. [2] In DNA viruses, the DNA transcribes itself into messenger RNA (mRNA) molecules that are then used to direct the cell's ribosomes. One of the first polypeptides to be translated destroys the host's DNA.
Some viruses (such as HIV, the cause of AIDS), have the ability to transcribe RNA into DNA. HIV has an RNA genome that is reverse transcribed into DNA. The resulting DNA can be merged with the DNA genome of the host cell. The main enzyme responsible for synthesis of DNA from an RNA template is called reverse transcriptase. [65]
Nucleic acid amplification is a technique used to produce several copies of a specific segment of RNA/DNA. [3] Amplified RNA and DNA can be used for a variety of applications, such as genotyping, sequencing, and detection of bacteria or viruses. [4] There are two different types of amplification, non-isothermal and isothermal. [5]