Attenuated measles vaccine (type)
Whole-agent. Live, avirulent virus that can cause the disease if it mutates back to its virulent state.
Dead Rickettsia Prowazekeii (type of vaccine)
Killed or Inactivated (Whole Agent)
Vibrio cholera toxoid (type of vaccine)
Subunit - inactivated toxin
Hepatitis B antigen produced in yeast cells
Recombinant Vaccine (Subunit)
Purified polysaccharide from Streptococcus Pyogenes (type of vaccine)
Haemophilus influenza polysaccharide bound to diptheria toxoid (type of vaccine)
Conjugated Vaccine (Subunit)
Plasmid containing gene for influenza A protein (type of vaccine)
DNA Vaccine (Subunit) Nucleic Acid
Why are monoclonal antibodies useful? (3 Reasons)
Name two drawbacks.
Advantages: They are:
2. Highly Specific
3. Can be produced in large quantities
1. Currently produced in mice
2. Murine proteins can cause immunological reactions in people
Explain the effects of excess antigen and antibody on the precipitation reaction.
Precipitation only occurs at the optimal ration of antigen/antibody. If there is an excess of one or the other, no visible precipitate will form.
Define the following terms and give an example of how each reaction is used diagnostically:
a. viral hemagglutination
b. hemagglutination inhibition
c. passive agglutination
A. viral hemagglutination - the ability to agglutinate red blood cells without an antigen-antibody reaction (ex. certain viruses that cause mumps, measles, and influenza). This type can be inhibited by antibodies that neutralize the agglutinating virus.
B. Hemagglutination Inhibition - a neutralization test used mostly for the serological typing of viruses. If a person's serum contains antibodies against viruses, the abs will react and neutralize the virus.
C. Passive agglutination - a sensitive method for antibody detection, in which the ab reacts with the soluble antigen adhering to the particles. The particles then agglutinate with one another, similar to the direct agglutination tests.
Explain the ELISA technique.
Direct ELISA detects antigens.
1. Ab is adsorbed to well. 2. Patient samples is added; complimentary antigen binds to ab. 3. Enzyme-linked ab specific for test ag is added and binds to ag, forming sandwich. 4.Enzyme's substrate is added and reaction produces a product that causes a visible color change.
Indirect ELISA detects antibodies.
1. Antigen is adsorbed to well. 2. Patient serum is added; complementary ab binds to ag. 3. Enzyme-linked anti-HISG is added and binds to bound ab. 4. Enzyme's substrate is added, and reaction produces a product that causes a visible color change.
What are the problems associated with the use of attenuated whole-agent vaccines?
Attenuated microbes may retain enough virulence to cause disease, especially in immunosuppressed individuals.
Modified viruses may occasionally revert to wild type or mutate to a virulent form.
How are immunological methods used to determine blood type?
Hemagglutination reactions, which involve red blood cell surface antigens and their complementary antibodies, are used routinely in blood typing and in diagnosis of infectious mononucleosis.
What are monoclonal antibodies? How are they produced? Why are they useful?
Ab molecules produced by a single hybridoma clone. They are produced by fusing an immortal cancerous B cell with a noncancerous antibody-secreting B cell. They can be maintained in culture indefinitely and can produce an immense amount of identical antibody.