S5 and S6 Molecular and Serological Diagnoses

anamnestic response

upon second encounter with same pathogen immune system mounts a faster, more intense, longer lasting response (Mostly IgG instead of the IgM-heavy primary response)

monoclonal antibodies

Antibodies produced by a single clone of B lymphocytes and that are therefore identical in structure and antigen specificity.

primary antibody

An antibody used to localize a specific protein or antigen, but which itself cannot be detected (used in ELISAs and Immunohistochemistry)

seroconversion

a change in serologic tests from negative to positive as antibodies develop in reaction to an infection or vaccine

thermal-stable polymerase

an enzyme which synthesizes new strand of DNA complementary to an existing single strand of DNA or RNA template in the 5'→3' direction but requires a short, double stranded region with a free 3' hydroxyl end for the enzyme to add the new nucleotide - used in PCR because it can maintain activity in the temps that melt DNA

ELISA

enzyme-linked immunosorbent assay - can be used to detect antibodies in serum or uses antibodies to detect a specific antigen in a sample. (COVID tests are a modified ELISA)

multiplex PCR

uses several sets of PCR primers to amplify more than one region of DNA in a single reaction - can test for multiple different pathogens in a single sample (this is how respiratory panels are run)

primer

a short stretch of RNA (replication) or DNA (PCR) with a free 3' end, bound by complementary base pairing to the template strand and elongated with DNA nucleotides during DNA replication or PCR

serology

The study of reactions between antibodies and antigens - typically using blood products (serum) to detect antibodies or testing blood serum for the presence of specific antibodies

titer testing

Tests for antibodies for a certain antigen

-Test to see if a person or animal really needs his next vaccine yet, also determines exposure to a given antigen

Hemagglutination inhibition

A test for detecting antibodies to certain viruses, based on lack of agglutination as a result of antibody neutralizing the virus.

PCR

(polymerase chain reaction) a method used to rapidly make multiple copies of a specific segment of DNA; can be used to make millions of copies of DNA from a very small amount of DNA

RT-PCR

A technique in which RNA is first converted to cDNA by the use of the enzyme reverse transcriptase, then the cDNA is amplified by the polymerase chain reaction.

SNPs

variations in the DNA sequence that occur when a single nucleotide in the genome is altered (single nucleotide polymorphisms)

virus neutralization

Neutralizing antibodies prevent virus attachment and entry into host cells. They bind to the viral capsid or host envelope.

MADLI-TOF

-matric assisted laser desorption/ionization time of flight

-laser causes ionization

-depending on mass and charge ratio

-"peptide fingerprint" database

-identifies specify proteins

polyclonal antibodies

a series of antibodies are produced responding to a variety of different sites on the antigen - typically made by injecting animals (eg rabbits) with a specific pathogen and harvesting serum several weeks later.

secondary antibody

An antibody which specifically binds to a primary antibody, and is conjugated to a detectable marker

template DNA

Piece of DNA that contains the region that needs to be amplified (area between the 2 primers - aka the target sequence)

Western blots

Designed to detect proteins using antibodies; Key Components: gel electrophoresis, transfer paper, antibodies; allows to detect a particular protein and quantify it