Laboratory Diagnosis Flashcards
2 types of examination
Direct and Indirect Examination
Specimen is what?
Examined Directly
what can be directly examined under a specimen
- Virus Particles
- Viral Antigen
- Inclusion Bodies
- Virus Nucleic Acid
what are the examination under direct examination
clue; ACCEN (asin)
- Antigen Detection
- Electron Microscopy
- Cytology (Light Microscopy)
- Classical Molecular Technique
- Newer Molecular Techniques
what are the test found under Antigen Detection
- Immunofluoresence (IF)
- ELISA (Enzyme-Linked Immunosorbent Assay)
- Latex Agglutination
Immunofluoresence (IF)
dye used
Dye Fluorescein Isothiocyanate
Immunofluoresence (IF)
Positive result
Apple Green Florescence with reddish brown counterstained cells
Immunofluoresence (IF)
Result
Viral antigen is detected or Viral antigen is not detected
what should be done with Immunofluoresence result?
- Should be correlated with clinical status of the patient
- Check the epidemiological situation
ELISA (Enzyme-Linked Immunosorbent Assay)
Positive Result
Color Formation
ELISA (Enzyme-Linked Immunosorbent Assay)
Types
- Solid Phase (test tube or microtiter plate)
- Membrane Bound (nitrocellulose membrane)
Latex Agglutination
Positve Result
Agglutination
Latex Agglutination
if the plasma contains anti bodies, what will happen
world stop
chz agglutination
Electron Microscopy - TOF
10 to the 6th virus particle per mL is required for visualization
True
i also dk what shes talking abt <3 - this is abt the micrscope
Electron Microscopy - TOF
electron micrscropy it can be made more sensitive, even at lower viral particles by using immunoelectron microscopy
T
Electron Microscopy
Magnification:
50,000 to 60,000
Cytology
uses what microscopy
Light Microscopy
Cytology
what does this detect
changes in cells
Cytology - TOF
checks for viral particles in cell
False
Cytology
Rapid diagnosis of viral infections that produce??
Cytopathic Effects (CPE)
Cytology
Characteristics of CPEs:
- Changes in cell morphology
- Cell lysis
- Vacuolation
- Syncytia
- Inclusion Bodies
Cytology - TOF
Sensitive and Specific
False
what are used under Classical Molecular Technique
- DNA/RNA probes for hybridization
Classical Molecular Technique
what are under the DNA/RNA probes for hybridization
- DOT blot
- Southern Blot
- In-situ hybridization (DNA in cell)
- FISH
Classical Molecular Technique - TOF
this techniques usually more tedious and expensive than the conventional techniques. Not widely accepted
True
what are the newer molecular techniques
- PCR (amplification technique)
- Commercial proprietary techniques
Newer Molecular Techniques
under pcr
- Real-time PCR
- RT-PCR
Newer Molecular Technique
Commercial proprietary techniques
- NASBA: Nucleic Acid Based Amplification
- LCR: Ligase Chain Reaction
- TMA: Transcription-Mediated Amplification
Indirect Examination
what is the first thing should be done
Virus Isolation
Indirect Examination
after virus isolation, what step should incur
Virus Identification
Indirect Examination
what are the can be used as a medium under viral isolation?
- Cell culture
- embryonated eggs
- chick embryo - seldomly used
- animals can also be used
Indirect Examination
what are the 3 types of Cell Cultures?
- Primary
- Semicontinuos (Secondary)
- Continous
What type of cell culture
- From normal adult tissue (usually monkey kidney)
- Can be subcultured (once or twice)
- Best cell culture system (Supports widest range of viruses)
- Very expensinve
Primary Cell Culture
What type of cell culture
- From Embryonic tissue – Considered as stem cell (kaya pwede ma subculture ng marami)
- Human embryonic kidney and skin fibroblast
Semicontinuous (secondary) cell culture
What type of cell culture
- From Malignaant Tissue (HeLa Vero. Hep2 LLC-MK2 and MDCK)
- Most easy to handle – cause its immortal cells
- Easier to grow – grow in resit surface (??) and suspension
- Can be subculture immortaly and indefinitely
Continous cell culture
if u see this card
go over the cell culture
what are the 2 factors to be considered in detection of the virus in culture?
- Presence of cytopathic effect
- Hemeadsorption
Detection of the Virus in Culture - under what factor
this maybe specific or non-specific
- Balloning of cells
- Syncytia formation
- Detaching of cells in the plate
Presence of cytopathic effect
Detection of the Virus in Culture - under what factor
Positive Result: Heme agglutination; carpet cell of red cell
Negative Result: Button cells
Hemeadsorption
what are the test under Conformation of the Identity of Virus
- Neutralization Test
- Hemagglutination Inhibition (HAI) Test
- Immunofluoresence
Conformation of the Identity of Virus
(Virus + specific Ab against virus) + different cell culture → NO Cytophatic Effect
Neutralization Test
Conformation of the Identity of Virus
(Virus + specific antibody) + RBC → NO hemagglutination
Hemagglutination Inhibition (HAI) Test
Virus (place in a slide) + specific Fluorescein-labelled antibody → Fluoresence
Immunofluoresence
A variation on standard tissue culture
Shell Vial Culture
Shell Vial Culture
what is the technique
A small bottle with a removable round glass coverslip is used to grow the cells as a monolayer on the coverslip
Shell Vial Culture
Result:
5-7 days
this is considered fast
if u see this card
go over the transes and study the process
also called as paired sera
Serology
Detect antibodies but it takes two week or more before positive result are obtained
Serology
Serology - TOF
also for detection of antigen in antibodies of viruses
True
Serology - TOF
Detection of rising titers of antibody
True
being check is increase in titer of antibody
Serology
Detection of ___ and ___ in primary infection
IgM (also IgG)
Serology
checking of IgM ONLY
detect primary infection
Serology
checking of IgM and IgG
positve for convalescent stage
Serology
checking of IgG only
infection has been resolved
what are the classic technique under Serology
- Complement Fixation
- Hemaagglutination-Inhibition Technique
- Immunofluorescent Technique
- Neutralization
- Counter Immunoelectrophoresis
what are the newer technique under Serology
- Enzyme immunoassay
- Particle Agglutination
- Western Blot
- RIBA (recombinant-immunoblot-assay)
- Line immunoassay
