M2 Lab Methods Flashcards
what is procedure
handling specimen
lab processing and reporting
interpretation and use of info
what do u do in lab analysis
isolate and identify organism
- sample
- timing
- handling
- request form
how is a sample taken fro purulent infection (pus forming)
aspirate of pus - drain
prevent contamination
maintain anaerobes
how to sample mucosal infections
yeast, swab and oral wash
herpes, lesions swab
how to sample caries and per disease
complex pic involving mix of organisms
how to do samples for culture
results = 2-5 days
streaked blood agar (aerobic/anaerobic)
colonies then indie cosines
antibiotic sensitivity
what does culturing do
determine viability (aerobes Vs anaerobes)
component species
provides pure material (single colony)
what is culturing sequence
primary inoculum
second streak
3rd streak
streak to single colonies
what is general media
transport media
- sloppy agar, incl charcoal prevents desiccation and abs toxic agents
rich excess of nutrients
what is enrichment media
addition of blood/serum/extracts will support growth of fastidious organisms
blood agar also - haemolytic profile determined
what si selective media
presence of specific substance permits the growth of one organism over another
what re some examples of selective media
mannitol salt agar
salmonela-shigella
what is differential media
incroportio of chems produces visible changes in colonies that facilitate identification
what are some examples of differentiate media
macconkay agar
- bile salts & crystal violet
eosin & methylene blue
what can be used for identification
microscopy - single colony or pus sample
- pure culture
- shape, size, grouping
- structures
- staining
what are the cocci structures
single
pair
cluster
chains
what are the rod bacilli structure
single
chain
curved rod
spiral
what is one species with many colony phenotypes
bacillus subtilis
what is metabolic profiling
biochem characterisation
utilisation of carbon sources and amino acids
what is exo enzyme production
catalase
coagulase
hydrolysis of lipid
urease
whats urease
urea converted to ammonia & CO2
what causes fermentation
lactose
what are serological tests
host immune response to Ag by rising of Abs
what are Ab specific to
microbe or single component
what else does serological tests do
detects presence of sp IgM Ab to virus
demo in vitro bu agglutination
rapid detection of viruses
serotype bac indeitifacton
what are immunological techniques
difficult to identify pathogens artificially raised sp antibodies - agglutination reactions - DFA test - ELISA
what is aggltination
antibody to antigen with latex bead - red blood cell
caring clot
what is DFA fluorescence tect
one step - org expo to Ab with attached dye, organism bind toAb and be seen
two step - similar to one step Ab at start not dye, instead secondary Ab dyed
what is ELISA
enzyme linked immunosorbent assay
how do u do ELISA
coat wells with antigen wash add antibody test wash add enzyme conjugate wash add chromogenic enzyme substrate and read colour change
what are virulence test
virulence factor can be critical in pathogenesis (adhesion, toxin)
in vitro antibody recognition, DNA hybridisation
what is DNA technology
sp primers amplify sp peice dna
PCR
what is MALDI-TOF
matrix assisted laser desorption ionisation time of fight
what are the features of MALDI_TOF
powerful
rapid
precise
cost effective
what does madli tof do
gen series of ions from a sample dept on its constituents
sep ions accord to mass
detects proteins
results in characteristic signature
