M2 PART1 Flashcards
- uses vaseline jelly
- longer observation of specimen
- doesnt dry out easily
HANGING DROP TEST
- uses light
- non viable (killed MO, except virus)
- stained
- arrangement, shape, and size
BRIGHT FIELD
- opauqe dark condenser
- unstained MO on dark background
- live, motility of cells
DARK FIELD
- annular diaphragm
- unstained, contrasted structures
- internal structures, live eukaryotes
- two shades of gray/black
PHASE CONTRAST
- shorter wavelength
- 0.2 um
- 100 - 2,00,000
- alternating light and dark areas contrasting internal cell structures
- ultrathin slices of MO
- electron microscope
TRANSMISSION ELECTRON MICROSCOPE
- 10 - 20,000
- surfaces and textures of MO and cell components
- microbial surfaces
- thin coat
SCANNING ELECTRON MICROSCOPE
- UV light
- outline of MO coated with flourescent-tagged antibodies
FLOURESCENCE
A process of artificially coloring microorganisms with dyes in order to facilitate their study under the microscope.
STAINING
it is an organic compound consisting of benzene rings.
DYES
The best bacterial stains are
ANILINE DYE
- positively-charged
- stains negatively charged
- ✓Examples: Crystal violet, safranin, methylene blue and malachite green
BASIC DYE
- negatively-charged
- stains basic/positively charged
- ✓Nigrosine, congo red, eosin and acid fuchsin
ACIDIC DYE
- combines basic & acidic
- methylene & eosin
NEUTRAL DYE
A thin film of material containing the MO is spread over the slide
SMEAR
The process of fixing MO or killing the MO and attaching them to the slide
FIXATION
Ways of fixation
✓Heat-fixing
✓Air-drying
✓Chemical fixation
Why is it important to fix the MO to the slides?
so it will not be washed away
for penetration
- A staining procedure that uses two or more dye
- A type of staining that reacts differently with different MO
PURPOSE:
✓ To contrast two or more organisms which maybe of the same or different species.
DIFERENTIAL STAINING
differential stain (GRAM STAIN) that was developed by ____ in 1884
HANS CHRISTIAN GRAM
It classifies bacteria as Gram + and Gram –
GRAM STAIN
GRAM STAIN
Primary stain
CRYSTAL VIOLET
GRAM STAIN
MORDANT
gram’s iodine
GRAM STAIN
DECOLORIZER
alcohol
GRAM STAIN
COUNTERSTAIN
Safranin
GRAM STAIN
STEPS
1-8
- Prepare
- Primary stain - Crystal Violet
- Mordant - Gram’s iodine
- Rinse - distilled water
- Decolorize - ethyl alcohol 95%
- Rinse
- Counterstain - Safranin
- Rinse, Dry, Observe
GRAM POSITIVE OR GRAM NEGATIVE
thick peptidoglycan
GRAM POSITIVE
GRAM POSITIVE OR GRAM NEGATIVE
thin peptidoglycan
GRAM NEGATIVE
GRAM POSITIVE OR GRAM NEGATIVE
90% peptidoglycan
GRAM POSITIVE
GRAM POSITIVE OR GRAM NEGATIVE
5 - 10% peptidoglycan
GRAM NEGATIVE
GRAM POSITIVE OR GRAM NEGATIVE
Teichoic acids
GRAM POSITIVE
GRAM POSITIVE OR GRAM NEGATIVE
NO teichoic acids
GRAM NEGATIVE
GRAM POSITIVE OR GRAM NEGATIVE
not many polysaccharides
GRAM POSITIVE
GRAM POSITIVE OR GRAM NEGATIVE
outer membrance has lipids, polysaccharide
GRAM NEGATIVE
GRAM STAINING
blue or purple color
GRAM POSITIVE
GRAM STAINING
pink or red in color
GRAM NEGATIVE
The Gram stain should be performed on a fresh ____ hour culture
18 - 24hour
GRAM STAIN
If the smear is not ____ or ____, or if the staining procedure is not performed correctly, the
cells will appear Gram-variable
thinly or evenly made
Which step is the most crucial or most likely to cause poor results in the Gram stain? and why?
decolorization
gram negative will look like postive
under decolorization
Bacteria that cannot be seen by Gram staining
Thick lipid layer containing mycolic acid
MYOBACTERIUM
Bacteria that cannot be seen by Gram staining
Atypical cell wall
MYCOPLASMA
- A differential stain developed by Franz Ziehl and Friedrich Neelsen.
- Binds strongly only to bacteria that have a WAXY material in their cell walls.
- It classifies the bacteria from acid-fast to non-acid fast.
ACID FAST STAIN
acid fast stain is developed by
FRANZ ZEIHL
FRIEDRICH NEELSEN
ACID FAST STAINING REAGENTS
PRIMARY STAIN
CARBOLFUCHSIN
ACID FAST STAINING REAGENTS
MORDANT
HEAT
ACID FAST STAINING REAGENTS
DECOLORIZER
ACID-ALCOHOL
ACID FAST STAINING REAGENTS
SECONDARY STAIN
METHYLENE BLUE
ACID FAST STAINING
STEPS
- Primary stain - Carbolfuchsin
- Mordant - heat
- Decolorizer - Acid alcohol
- Counterstain/Secondary stain - Methylene blue
ACID FAST microorganisms
MYOACTERIUM
NOCARDIA
ACID FAST MO
has large amount of lipids
MYOBACTERIUM
ACID FAST MO
partially acid fast
NOCARDIA
- “Indirect staining”
- Preparing colorless bacteria against a colored background
- Reagent: Nigrosine or India Pink
NEGATIVE STAINING
NEGATIVE STAINING reagent
Nigrosine
India Pink
Staining procedure used to color, isolate, identify and study specific parts or structures of MO
SPECIAL STAINING
SPECIAL STAINING
✓Flagella Staining
✓Spore staining
✓Capsule staining
ENDOSPORE staining is also called
Schaeffer-Fulton Endospore stain
special resistant, dormant structure formed within a cell that PROTECTS a bacterium from adverse ENVIRONMENTAL CONDITION
ENDOSPORE
ENDOSPORE STAINING REAGENTS
PRIMARY STAIN
Malachite green
ENDOSPORE STAINING REAGENTS
DECOLORIZER
ACID ALCOHOL
ENDOSPORE STAINING REAGENTS
SECONDARY STAIN
SAFRANIN
ENDOSPORE STAINING
identifies what organisms
BACILLUS
CLOSTRIDIUM
ENDOSPORE STAINING
spores may be located
terminal
central
subterminal
CAPSULE staining is also called
WELCH METHOD
A staining technique that stains the bacteria and the background leaving the capsule unstained
CAPSULE STAINING
CAPSULE STAINING REAGENTS
PRIMARY STAIN
CONGO RED / NIGROSIN
CAPSULE STAINING REAGENTS
MILD DECOLORIZER
COPPER SULFATE
CAPSULE STAINING
identifies what organisms
Streptococcus pneumoniae
Cryptococcus neoformans
capsule is ____
non ionic
