Term
| What are the types of antibodies used for diagnostic purposes? |
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Definition
| polyclonal and monoclonal |
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Term
| How are polyclonal antibodies developed? |
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Definition
| animals repeatedly immunized to develop high antibody level (protein can be organism of interest, protein from wall or human antibodies) |
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Term
| how are monoclonal antibodies developed? |
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Definition
when animal spleen cells are fused with malignant myeloma cells
- cells are then selected for those that produce only one kind of antibody in a very high (and pure) amount |
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Term
| Measuring IgM antibodies are usualy a reflection of what? What are some examples? |
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Definition
reflection of a recent infection
ex. measles, rubella, hep A |
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Term
| Rising levels of IgG often indicate what? Example? |
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Definition
recent infection (often a 4-fold increase but depend on method)
eg. respiratory viruses
* note, any IgG antibody = past infection: ex. HIV, or HCV |
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Term
| What does a very high titre of antibody signal? Example? |
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Definition
| recent infection; eg. Legionnaires disease |
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Term
| What is measuring antibodies in patients serum able to tell us? |
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Definition
| detect infection and determine immunity |
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Term
| How are antibody levels detected? |
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Definition
| usually by enzyme linked immunosorbet assays (ELISA) or enzyme immuno assay (EIA) |
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Term
| List the steps of ELISA or EIA..? |
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Definition
- coat plastic well with proteins (antigens)
- add patient serum (antibodies if present stick to antigens)
- wash well (remove all other antibodies)
- add anti-antibody tagged with enzyme = sticks to antibody
- add substrate for enzyme to react
- turns colour of well
- measure amount of colour
- more colour = more antibody; no color = no antibody
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Term
How are antigens detected in serum?
list the steps of ELISA.
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Definition
by ELISA (?) and particle agglutition tests
- well plate coated with specific antibody
- patient specimen added to tube
- well washed = remove non sticking Ag
- second antibody added = tagged with enzyme
- enzyme substrate is added and colour change seen if present
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Term
| Examples of EIA detected antigens |
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Definition
| Hep B surface antigen HBsAg |
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Term
| Examples of antibody detection for things? |
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Definition
| measles, HIV, Hep A, B or C |
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Term
| How do we detect antigens that are in tissue as a result of infection? |
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Definition
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Term
List the steps of fluorescence microscopy.
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Definition
- put specimen on slide and dry
- add antibody to antigen or organism looking for
- incubate so antibody sticks
- wash off well; all unattached antibody washed
- look under to see if cells fluorescent (special microscope)
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Term
| Detecting influenza or RSV infected cells from the naso-pharyngeal swab is an example of what? |
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Definition
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Term
| Detecting herpes virus infected cells scraped from base of ulcers is example of what? |
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Definition
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Term
| Detecting varicella zoster virus in cells scraped from base of chickenpox lesion is example of what? |
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Definition
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Term
| detecting pneumocystis in a sputum sample is an example of what? |
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Definition
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Term
| List the steps of detecting antigens using a single use mini ELISA kit. What are you detecting? |
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Definition
- take throat swab
- treat it to extract streptococcal antigens
- put drop in device
- let diffuse along filter till comes up to antibody in filter paper (will stop here and bind)
- add enzyme tagged antibody to sandwich the antigen
- add drop of enzyme substrate and observe for colour change
detecting strept throat! |
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Term
| What can you detect with mini ELISA kit? |
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Definition
| strep and pregnancy! (and HIV?) |
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Term
| List the steps in detecting pregnancy. what do you use? |
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Definition
single use mini ELISA kits
- take urine specimen
- put drop in device
- let difuse along filter till come to antibody (stop here and bind)
- add enzyme tagged antibody to sandwhich antigen
- add drop of enzyme substrate and observe for colour change
looking for hCG |
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Term
| List the steps of particle agglutition test |
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Definition
- speciman (ex. spinal fluid or bacteria from culture) mixed with tiny beads coated with specific antibodies
- IF the specimen contains antigens (bacterial proteins); the particles come together and look granular (they agglutinate)
- spinal fluid antigen test may be positive, even in patients who recieved antibioitcs after cultures negative
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Term
| what can the particle be in the particle agglutition test? |
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Definition
| latex particle (bead of gelatin) |
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Term
| Can you use the particle agglutition test to detect antibodies? What do you change to do this? |
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Definition
yes. you coat beads with antigens instead of antibodies
add patient serum, if have antibodies to antigen will agglutinate |
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Term
What are examples of detecting antibodies with particle agglutination tests?
What is this the basis of? |
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Definition
| syphilis and mononucleosis (basis of monospot!) |
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Term
| How do we use cellular immune response to diagnose infections? |
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Definition
| TB skin test! Montoux test |
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Term
| Skin testing is most often used for what type of diagnosis? |
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Definition
| cellular immune response diagnosis |
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Term
| How does the Mantoux test work? |
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Definition
- TB antigen injected under skin (5 TU)
- over 48 hours, cells migrate toward injection antigen
- produce local swelling (induration); diameter of induration is measured
- individuals without past TB have no induration
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