Why is it important to keep books, coats and packs away from lab tables and chairs?
All of the above
What should you do before starting any lab exercise
Wash hands with soap and warm water
How should you hand a culture spill in the lab
Report to the instructor for proper disinfectant procedure
Which of the following not allowed in the lab
eating food
what personal protective equimen is recommened in the lab
all of the above- eye protection, lab coats and gloves
how should inoculation loops and needles be treated befroe and after use
flamed
what should be done to prevent aerosols when using needles and loops
flame and cool them properly before use
how should test tubes and other culture vessels be handled to maintain sterility
flame the mouth of the vessels
where should contaminated disposable waste be discarded
in the autoclavable bags
what must students do at the beginning of the term regarding lab safety rules
sign a copy of the laboratory safety agreement
what is meant by the term aseptic technique
techniques to avoid contamination
where should you label your agar plates and how should they be stored
on the bottom and stored upside down
why should you wait for your loop to completely cool before attempting a bacterial transfer
to avoid killing the bacteria
how do you prevent air contamination of agar plates if they are not flamed
keep the lid partially closed
when you remove the lid of a test tube or agar plate is it ok to set it on a clean work bench whule you re ove or add bacteria
false
the opening of the test tubes and the lid should be passed through the flame before the lid is replace on the tube
true
it is ok for one group member to hod a test tube while another member extracts bacteria from it for a transfer
false
what should be done to the workspace before starting bacterial transfers?
clean it with bench disinfectant or bleach and remove clutter
why should bacterial transfers be done close to the flame of a bunsen burner
to reduce contamination from airborne microbes
how should test tubes be handled to prevent spills
hold the tube and not the cap
what is the correct way to mix broth cultures before transfer
swirl the tube in your hand
what should be done to the inoculating loop before picking up cells
allow it to completely cool after flaming
how should the cap of a test tube be handled during a bacterial transfer
grasp it between the ring and pinky fingers and the palm
what should be done if a spill occurs during bacterial transfer
clean it up immediately with 10% bleach or bench disinfectant
hwo should bacterial cultures be labeled
on the bottom of the plate
what is the purpose of the ubiquity exercise
to illustrate the variety of bacteria from a source of your choosing
what can be used for the initial isolation of your sample besides a dry sterile swab
a moist swab
what should you do after dipping the sterile swab into sterile saline or water
push the swab against the side of the test tube to squeeze excess water
what is used to isolate bacteria from a source of your choosing
a dry sterile swab
what type of agar is used for streaking plate technique
nutrient or tryticase agar
at what temperature should the plates be incubated
37 c
for how long should the plates be incubated
24 to 36 hrs
what should you do after the incubation period
observe the plate for growth
what is the primary purpose of the gram stain technique
to differentiate between gram positive and gram negative bacteria
which of the following is the primary stain used in the gram stain technique
crystal violet
what is the role of iodine in the gram stain process
to act as a mordant and fix the crystal violet stain
what color do gram positive bacteria appear after the gram stain procedure
purple
what cell wall component does the decolorizing agent in the gram stain technique effect
peptidoglycan
which of the following is used as the counterstain in the gram stain technique
safrarin
what is the typical shape of cocci bacteria
spherical
how are bacteria arranged in a streptococci formation
in chains
what is the approximate size range of most bacteria
1 to 10 micrometers
what is one of the most important steps in identifying a new bacteria or one isolated from a patients specimen
noting colony morphology
what can cause variations in colony morphology
nutrients present in various media or incubation conditions
which bacteria are not cultured in the lab due to being pathogens or having unavailable growth conditions
mycobacterium, mycoplasma, chlamydia, rickettsia
why are mycoplasma species pleomorphic
they have no cell wall
what is the purpose of the acid fast stain
to identify mycobacterium and related bacteria
what is used to stain the waxy cell wall of mycobacterium in the acid fast stain
carbolfuchsin
what is the function of bacterial capsules in some strains
to protect the microbe from host defense mechanisms
what staining technique is used to visualize bacterial flagella
special staining techniques with a stain and mordant
which genera of bacteria are most characteristics of endospore formation
bacillus and clostridium
what stain is used to visualize endospores in bacillus cultures
malachite green
what is the purpose of perfroming gram stains on organisms after observing colony morphology
identify some cell wall components and cellular morphology
what special stains are available for identifying bacterial surface structures or internal components
capsule stain and flagella stain
what unique component in the cell wall ofmycobacterium prevents it from staining with simple and gram stain
mycolic acids
what is the counterstain used in the acid fas stain to visualize non acid fast bacteria
methylene blue
why is acid fast stain important for diagnosing mycobacterial diseases
mycobacterium grows very slowly in culture
what is the purpose of using a mordant in flagella staining
to increase the diameter of the flagella for viewing
what is the apperance of endosores after staining with malachite green and safranin
green in red bacterial cells
what is the purpose of the science of taxonomy
to classify and name organisms
which of the following domains contains orgamisms with prokaryotic cells
both b and c
in the hierarchical taxonominc system similar species are placed into the same
genus
what distinguishes the bacterial phyla firmicutes and actinobacteria
the percentage of guanine and cytosine bases in their DNA
which of the following genera is not part of the firmicutes phylum
mycobacterium
what is unique about the metabolic strategy of cynobacteria
they utilize oxygenic photosynthesis
which genus with proteobacteria phylum is known for nitrogen fixation
rhizobium
what is the unique about the cell walls of bacteria in the phylum chlaydiae
they have little or no peptidoglycan
what materials are needed to study the morphology of key bacterial genera
prepared slides microscopes and staining materials for
what should be included on the flashcards for each bacterial phylum
the phylum name characteristics and names of key genera
which phylum has a gram positive reaction and a low g&c content in dna
firmicutes
what is the dominant metabolic strategy of actinobacteria
chemoheterotrophy
which key genera belong to the firmicutes phylum
bacillus clostridium lactobacillus
what is unique about the cell walls of bacteria in the chlamydiae phylum
they lack peptidoglycan
which phylum includes bacteria that perform oxygenic photosynthesis
cynaobacteria
which is key genus is part of the actinobacteria phylum
mycobacterium
what is the gram reation of proteobacteria
negative
which phylum is known for its highly diverse genera
proteobacteria
which key genus is associated with the cyanobacteria phylum
anabaena
what is the dominant metabolic strategy of cyanobacteria
oxygenic photosynthesis
which genus is common in soil and forms endospores
bacillus
which genus is known for lactic acid oroduction and is important in food production
lactobacillus
which genus is associated with the human gut and includes both normal microbiota and some human pathogens
escherichia
which genus is known for its resistant waxy cell wall and includes pathogens that cause tuberculosis and leprosy
mycobacteria
which genus is found in root noodules of plantsand is involved in nitrogen fixation
rhizobium
which genus is a common toxic food contaminant and obligate anaerobe
clostridium
which genus is known for fillamentous growth and is a source of manyantibiotics
streptomyces
which genus performs oxygenic photosyntheses and nitrogen fixation
anabaena
which genus lacks peptidoglycan in its cell walls and includes many human pathogens
bacillus
which genus has flagella on both ends and is found in stagnant water
spirillum
what charge do most bacterial stains have
postive
what is the purpose of negative stains like congo red and india inl
to stain the background
what is the total magnification when using a 10x ocular and a 100x objective
1000x
at what magnification will you not see indivudual bacteria
less than 400x
what is the function of the condenser in a microscope
to focus light on the specimen
what does the term parfocal mean in microscopy
the specimen will almost be in focus when changing objectives
how are staphylococcus bacteria arranged
clusters of spherical bacteria
what is the function of immersion oil in microscopy
to improve resolution by matching the refractive index of glass
what is the function of the condenser in a micrscope
to focus the light on the specimen
what is the purpose of immersion oil when using the 100x objective
to improve resolution of
what is the function of the iris diaphragm in a microscope
to control the amount of light passing through the
why do you intially focus on the wax pencil mark
to ensure the slide is in the correct position
what does streptococcus refer to
chains of spherical bacteria
where do discard used slides in the lab
in a designated sharps container
what is the primary instrument for viewing bacteria in lab
compound microscope
how is the total magnification calculated
objective ocular
what happens to the working distance as the magnifying power of the lens increases
it decrease
what does rp resolution refer to in microscopy
ability to distinguish two points as separate
what is the numerical aperture na of a lens
the light gathering capacity of the lens
how should a microscope be carried
with both hands one holding the arm and one under the base
what should be used to clean the oculars objectives and condenser lenses
lens cleaner
what should be done at the end of each microscope session
remove the slide wipe oil and place the scanning objective in a vertical position
what is purpose of staining in microbiology
to increase contrast between bacteria and the slide
what is the first step in a smear preparation from the plate or brothq
begin with a clean and dry slide
what stain isused in the simple stain procedure
methylene blue or safranin
what is th epurpose of the negative stain procedure
to stain the background and leave the bacteria unstained
what is used to spread the drop of bacteria and stain in the negative stain procedure
the edge of a second clean slie
what is the purpose of a wet mount
to observe living organisms in a liquid environment
what should be used to cover the drop of hay infusion liquid in a wet mount
a coverslip
what should be done if a gram positive organisms are staining as gram negative
lengthen the crystal violet and mordant step and shorten the decolorizer step
what is the possible cause if no organism is visible
overheating the smear
what could cause organisms to appear clumped on a slide
too many organisms on a slide
if the smear appears granular under oil what might be the cause
lens is dirty or condenser is too low
what should be done if gram positive organisms appear pink
use fresh culture
what could causee gram negative organisms to appear blue
improper decolorization of