Lab Practical 1 Flashcards
Brightfield microscope
allows light rays to pass directly through the eye
stage
horizontal platform that supports the microscope slide
light source
provides light through a voltage control
neutral density
reduces light intensity
ocular
two lenses to see through
objectives
name of the different strengths
what are the three objectives
low power high dry oil immersion
condenser
directs light to the slide
resolving power
ability to separate two objects
what can maximize resolving power?
blue filter immersion oil
what does bacteria’s cell wall made of?
peptidoglycan
what are the three shapes of bacteria
rod - bacilli spherical- cocci spirals- curved rods
are cocci motile?
no
cocobacillus
Bacillus
Fusiform
what are axial filaments
what allows spriocheates to be motile
what is aseptic technique
ensures there are no contaminants
what is a pure culture
isolating one bacteria from many
what are the two procdures for a pure culture
pour plate and streak plate
what are the types of streaking
quadrant
continuous
staphylococci
what is an example of a differential stain
gram stain
what colour is gram positve
purple
what colour is gram negative
pink
what is a primary stain
crystal violet
why are gram postive pruple?
thick walls of peptodoglycan
what is the mordant in the gram stain?
iodine
what does iodine do in a gram stain?
forms an insoluble complex in gram positive
how is iodine removed in gram negative cells?
alchohol
what is the decolorizer in gram negative
alcohol or acetone solution
what is the counterstain
safranin
what does safran DO
attached to lipid layer
what are the two methods of spore staining
dorner and shaeffer fulton method
simple stain
capsule stain
endospore stain
gram stain
acid fast
gram positive pruple
gram negative pink
what is the shaefer fulton method of spore staining
uses malachite green to stain endospore and safranin to stain vegetation
what species to endospore belong to?
bacillus or clostridia
what is the protein coat on an endosperm called
endosporium
how can endospores be destroyed
autoclave
what does the dorner method involve
Nigrosin is used to make a black endospore
what is myolic acid
waxy material that coats cell
what is the primary stain in acid fasting
carbolfuchsin
what is the purpose of phenol in acid fast staining
allows carbolfuchsin to penetrate waxy coat
what is the differerence between acid fast and non-acid fast
acid fast cannot be decolorized
non acid fast can be decolorized
what must non-acid fast be counterstained with
methyl blue
what colour are non acid fast cells
blue
what colour are acid fast cells
pink
what causes motion in becteria
flagella
what is cheotaxis
move away from harmful bacteria
what kind of rings do gram positive cells have
s and m
