Microbiology 201 lab RUBENSTEIN IVY
TECH
What is aseptic technique? - ANS-practices that reduce or eliminate the transfer of
bacteria between patients and healthy care workers collectively
what is a hospital acquired or nosocomial infection? - ANS-illness that results from the
inadvertent infection of a patient or healthcare worker while they are in the healthcare
setting
What is an endospore? - ANS-structure produced by bacteria that allow them to survive
in environments that would kill normal vegetative cells
how would you ensure you keep your specimen sterile? - ANS-ensure you flame before
and after using/opening or dipping items. Keep items closed when not using and ensure
the flamed area doesn't touch anything
when using a pipette to measure out water, do you flame that pipette first? - ANS-no,
the pipette is made of plastic and will melt. the pipette comes in sterile packaging.
who were the first scientists that proposed the aseptic techniques? - ANS-lister and
semmelweis
when should you wash your hands when seeing a patient? - ANS-before and after
what is normal or residential flora? - ANS-the skins bacteria that live between cells of
epidermis
what is transient flora? - ANS-bacteria that can't colonize on the skin
the dermis tissue of the skin is considered axenic. what does this mean? - ANS-it is free
of microorganisms
how do you count the colonies on the petri dish if there seem to be >100? - ANS-you
would draw 5 1cm squares. you would then make a table(1-5 in each box)then count
the colonies in the squares and add them to the table. add up all the colonies and divide
by 5. once you find the average you would then multiply it by 57cm^2
, if the colonies on the petri dish are <100, what would be your next step? - ANS-you
would just count the colonies and that would be the total on the plate (DO NOT divide
by 5 or multiply by 57cm^2)
how do you determine the concentration of bacteria? (bacteria per ml) - ANS-take the
number of colonies on the petri dish and divide it by the amount of effluent volume
added (ex.410.4 colonies/plate X .4 ml)
how do you determine the total number of bacteria in the beaker? - ANS-take the
bacteria per ML and multiply it by 500 ml (size of beaker)
given the information below, do the steps to find the total number of bacteria in the
beaker:
petri dish size: 57cm^2
beaker: 500 ML
volume of effluent plated: 0.2ML
box 1: 14 colonies
box 2: 10 colonies
box 3: 11 colonies
box 4: 14 colonies
box 5: 13 colonies - ANS-total number of colonies: 14+10+11+14+13=62
62/5= 12.4
12.4X5cm^2= 706.8 colonies per plate
706.8/0.2ML= 3534 bacteria per ML
3534X500ML= 1,767,000 bacteria in 500 ML beaker
what is a clinical specimen? - ANS-urine, sputum, CSF
what is the difference between a mixed and a pure culture? - ANS-mixed: clinical
specimens that contain several species of bacteria
Pure: culture consists of cells of a single specimen
how do you do a T-Streak? - ANS-1. on petri dish, draw a T
2: follow the 1-3 steps on picture
what is it called a compound microscope? - ANS-the image is magnified by 2 sets of
lenses
what is the base of the microscope? - ANS-stable platform that provides support
TECH
What is aseptic technique? - ANS-practices that reduce or eliminate the transfer of
bacteria between patients and healthy care workers collectively
what is a hospital acquired or nosocomial infection? - ANS-illness that results from the
inadvertent infection of a patient or healthcare worker while they are in the healthcare
setting
What is an endospore? - ANS-structure produced by bacteria that allow them to survive
in environments that would kill normal vegetative cells
how would you ensure you keep your specimen sterile? - ANS-ensure you flame before
and after using/opening or dipping items. Keep items closed when not using and ensure
the flamed area doesn't touch anything
when using a pipette to measure out water, do you flame that pipette first? - ANS-no,
the pipette is made of plastic and will melt. the pipette comes in sterile packaging.
who were the first scientists that proposed the aseptic techniques? - ANS-lister and
semmelweis
when should you wash your hands when seeing a patient? - ANS-before and after
what is normal or residential flora? - ANS-the skins bacteria that live between cells of
epidermis
what is transient flora? - ANS-bacteria that can't colonize on the skin
the dermis tissue of the skin is considered axenic. what does this mean? - ANS-it is free
of microorganisms
how do you count the colonies on the petri dish if there seem to be >100? - ANS-you
would draw 5 1cm squares. you would then make a table(1-5 in each box)then count
the colonies in the squares and add them to the table. add up all the colonies and divide
by 5. once you find the average you would then multiply it by 57cm^2
, if the colonies on the petri dish are <100, what would be your next step? - ANS-you
would just count the colonies and that would be the total on the plate (DO NOT divide
by 5 or multiply by 57cm^2)
how do you determine the concentration of bacteria? (bacteria per ml) - ANS-take the
number of colonies on the petri dish and divide it by the amount of effluent volume
added (ex.410.4 colonies/plate X .4 ml)
how do you determine the total number of bacteria in the beaker? - ANS-take the
bacteria per ML and multiply it by 500 ml (size of beaker)
given the information below, do the steps to find the total number of bacteria in the
beaker:
petri dish size: 57cm^2
beaker: 500 ML
volume of effluent plated: 0.2ML
box 1: 14 colonies
box 2: 10 colonies
box 3: 11 colonies
box 4: 14 colonies
box 5: 13 colonies - ANS-total number of colonies: 14+10+11+14+13=62
62/5= 12.4
12.4X5cm^2= 706.8 colonies per plate
706.8/0.2ML= 3534 bacteria per ML
3534X500ML= 1,767,000 bacteria in 500 ML beaker
what is a clinical specimen? - ANS-urine, sputum, CSF
what is the difference between a mixed and a pure culture? - ANS-mixed: clinical
specimens that contain several species of bacteria
Pure: culture consists of cells of a single specimen
how do you do a T-Streak? - ANS-1. on petri dish, draw a T
2: follow the 1-3 steps on picture
what is it called a compound microscope? - ANS-the image is magnified by 2 sets of
lenses
what is the base of the microscope? - ANS-stable platform that provides support
