SARS-COV-2 Flashcards
How to detect COVID
Knowing the genome sequence allows us to create specific oligonucleotide primers.
RT-PCR from swabbing allows us to detect it. 100% accurate but is time consuming and costly
Antibodies of SARS-CoV-2 in patients can be made in animals (monoclonals in mice) or synthetically made proteins as antigens.
Antibody test-
Spike 2 production from virus grown in culture.
Can be done at home but far less accurate.
What are isothermal methods
Non PCR methods of amplifying
Recombinant polymerase amplification (RPA)-
DNA primers incubated with recombinase (uvsx). The primers will bind to complementary DNA and force the two strands apart. ss binding proteins will stabilise displaced strand.
Bsu (strand displacing polymerase) replicates DNA between the two primers and then this is amplified.
How does cas13 work
When activated by guide RNA that is complementary to specific target DNA, cas13 undergoes conformational change becoming activated.
Activated cas13 cleaves both target DNA by cos cleavage and reporter molecules (flurophore and quencher) by trans cleavage. This can then be detected which allows you to find where the viral RNA is.
How is mRNA used as a vaccine for COVID
mRNA encodes for a viral protein like spike protein found on the outer membrane of SARS-CoV-2.
It’s injected into host and protein is produced in cells which the immune system recognises as foreign and will mount an immune response against it
Why would self replicating RNA constructs require small doses of RNA vaccines
Due to their ability to amplify within a host cell. They consist of antigen genes as well as genes necessary for RNA replication.
Alpha viruses encode an RNA dependent RNA polymerase to that can replicate their genome.
