Antibodies & diagnostics Flashcards Preview

MCD - Diagnostics > Antibodies & diagnostics > Flashcards

Flashcards in Antibodies & diagnostics Deck (12):

Give examples of what can be attached to antibodies for diagnostic purposes

  • Enzymes: e.g. peroxidase, alkaline phosphatase
  • Fluorescent probes: dyes, beads of different sizes
  • Magnetic beads: e.g. purification of cell types
  • Drugs: e.g. Kadcyla, anti-HER2 linked to emtansine


List 3 ways antibodies can be manufactured

antisera from immunised animals (polyclonal) monoclonal antibodies “genetically engineered” antibodies


How are monoclonal antibodies produced?

  • immunise mouse
  • take out spleen
    • source of cells producing HGPRT+ve antibodies but have limited cell division.
  • These cells are fused with immortal HGPRT-ve myeloma cells to form hybridomas
  • Culture in a medium selective for HGPRT+ve cells
  • Clone cells by limiting dilution
  • Harvest antibodies produced by cells.


With examples list the therapeutic uses of antibodies

  • Drugs - targeting drugs to certain cell types e.g. breast cancer Kadcyla - anti-HER2 linked to emtansine
  • Prophylactic protection against microbal infection - synagis to protect from respiratory syncytial virus
  • Removal of t-cells from bone marrow grafts prevent graft vs host disease (Anti-CD3)
  • Block cytokine activity (anti-TNFα)


list examples of types of substance that are identified diagnostically by antibodies

  • Blood group serology
  • Immunoassays
    • hormones
    • antibodies
    • antigens


How are genetically modified antibodies produced?

Take the V section gene of an antibody and fuse it with a bacteriophage coat protein - displays V section on its surface


Create a library of these 


Add the library to the antigen and wash unbound phage away 


Expand the right phage population


What is serum electrophoresis?

Electrophoresis of blood antibodies, shouldnt see thin dense bands - bands should be spread out more


How can serum electrophoresis be used?

If a single band is very dense - indicates monoclonal expansion Could be B-cell malignancy Investigate for myeoma


How does ELISA work?

Washed after adding antibody to remove any unbound antibody

If colour change detected = positive result


With an example how does rapid testing work?

Pregnancy testing


What is flow cytometry?

Antibodies to specific antigens labelled with florescent markers

Mixed with cells

Bind to cells with their antigen

Passed through machine 

laser meaures size granulation and floresence.


What kind of conditions is immunodiagnosis useful for?

  • Infectious diseases
  • Autoimmunity Allergy (IgE)
  • Malignancy (myeloma)