Non-Core Lab and Qualitative Analysis Flashcards
types of samples processed by anatomic pathology
tissue from anywhere in body
samples processed by hematopathology
blood, bone marrow, body fluids like CSF
samples processed by microbiology
samples from everywhere
6 processes Microbio can use to test samples
- culture - agar plates
- biochemical reactions
- microscopy : light, fluorscence
- serology - nucleic acids
- molecular analysis
- mass spectrometry
what is cytology
suspension of cells in fluid
stains - what do they provide? 2commonly used?
important to provide contrast when viewing.
- hemotoxylin - basic, binds negative charge.
- eosin - acidic, binds positive charge
define grossing
examining a specimen macroscopically.
ID, measurements, descriptions, sectioning
3 goals of fixation
preservation of tissue
inactivation of infectious agent
hardening of tissue
good fixation needs (4)
- adequate amount of fixator
- adequate time
- thin enough tissue for adequate penetration
- appropriate temperature
define ischemic time
time between removal of tissue from body to time placed in fixative
most commonly used fixative
- how it works, benefits, disadvantages.
- bone - how is it fixed?
formaldehyde.
cross-links protein, cheap, compatible with later tests. toxic - handing, need good ventilation
bone fixed by decalcifying.
3 step processing to form FFPE
- dehydration - remove water in tissue, replace with alcohol
- clearing: remove alcohol and replace with xylene
- infiltration: introduce embedding medium to make tissue stiff enough to be thinly sectioned - paraffin
define FFPE
formalin fixed, paraffin embedded
where do you cut tissue? how thick is tissue after cutting?
microtome 4 um
define immunohistochemistry
detect protein expression using antibody binding on tissue of interest. primary or secondary. add enzyme that produces colour to last antibody to visualize anitbody interaction.
