MICROBIOLOGY MID
TERM-LAB 2024
,MICROBIOLOGY MID TERM-LAB
1
What is a smear? –
answers-A thin film of material containing microorganisms spread over the
surface of a clean microscope slide
Sucess at bacterial staining depends on what?
- answers-preperation of a suitable smear of the organism
What is heat-fixing?
- answers-using a flame; the heating of a smear on a slide briefly and gently.
partially melts the cell walls of bacteria
What are the three things Heat-fixing does?
- answers-
1: causes the cells to adhere to the slide so it won’t wash off
2:Kills the microorganisms
3:Causes changes in the bacterial cells which causes them to stain better
Hows does Heat-Fixing work? - answers-It removes water from the bacterial cell,
pores open in the cell so more stain can enter the cell wall.
A good heat-fixes smear should be able to do what 2 things?
- answers-1. Must be able to withstand ane or more washings w/out the loss of
microorganisms
2.Does not result in excessive cell distortion ***heat-fixing always results in some
degree of cell distortion,
Name 7 things that may go wrong in heat-fixing.
- answers-
1.Over heat; incincerated cells will not stain
2.Under heat;if bacteria cells aren't killed, their ability to accept stain is altered
, MICROBIOLOGY MID TERM-LAB
2
3.Must be Air-Dried; if not organism could be boiled and rupured and will not
adhere to slidw
4.Too thick; light cannot pass, you cannot see individual cells
5.Too Thin; not enough cells to stain or see
6.Liguid broth;may be too little cells;use 2-3 loopfuls to compansate
7.Solid media (Agar);colonies are here and may have too many;dilute with 1-2
looful of distilled water.
Steriliazation - answers-It is an absolute value : 100%
-The complete destruction or removal of all microbes, including viruses(nonliving)
& endospores(Resting)
How are the organisms killed? - answers-Steam; dry heat; incineration
Define Disinfection. - answers-A process in which vegetative microorganisms are
destroyed on non-living objects and surfaces
What does vegetative mean?
- answers-Actively growing
What is the number 1 agent for disinfection?
- answers-Bleach
What are the 3 definitions of Sepsis?
- answers-
1:The growth of microorganisms in normally sterile tissues of the body
2:Decay, contamination,putrification
3:The presence of bacteria in blood that ate ectively multiplying (Serious)
Define ASEPSIS - answers-A medical tem, any procedure that prevents the
entrance of infectious agents into sterile tissue, thus preventing infection.
TERM-LAB 2024
,MICROBIOLOGY MID TERM-LAB
1
What is a smear? –
answers-A thin film of material containing microorganisms spread over the
surface of a clean microscope slide
Sucess at bacterial staining depends on what?
- answers-preperation of a suitable smear of the organism
What is heat-fixing?
- answers-using a flame; the heating of a smear on a slide briefly and gently.
partially melts the cell walls of bacteria
What are the three things Heat-fixing does?
- answers-
1: causes the cells to adhere to the slide so it won’t wash off
2:Kills the microorganisms
3:Causes changes in the bacterial cells which causes them to stain better
Hows does Heat-Fixing work? - answers-It removes water from the bacterial cell,
pores open in the cell so more stain can enter the cell wall.
A good heat-fixes smear should be able to do what 2 things?
- answers-1. Must be able to withstand ane or more washings w/out the loss of
microorganisms
2.Does not result in excessive cell distortion ***heat-fixing always results in some
degree of cell distortion,
Name 7 things that may go wrong in heat-fixing.
- answers-
1.Over heat; incincerated cells will not stain
2.Under heat;if bacteria cells aren't killed, their ability to accept stain is altered
, MICROBIOLOGY MID TERM-LAB
2
3.Must be Air-Dried; if not organism could be boiled and rupured and will not
adhere to slidw
4.Too thick; light cannot pass, you cannot see individual cells
5.Too Thin; not enough cells to stain or see
6.Liguid broth;may be too little cells;use 2-3 loopfuls to compansate
7.Solid media (Agar);colonies are here and may have too many;dilute with 1-2
looful of distilled water.
Steriliazation - answers-It is an absolute value : 100%
-The complete destruction or removal of all microbes, including viruses(nonliving)
& endospores(Resting)
How are the organisms killed? - answers-Steam; dry heat; incineration
Define Disinfection. - answers-A process in which vegetative microorganisms are
destroyed on non-living objects and surfaces
What does vegetative mean?
- answers-Actively growing
What is the number 1 agent for disinfection?
- answers-Bleach
What are the 3 definitions of Sepsis?
- answers-
1:The growth of microorganisms in normally sterile tissues of the body
2:Decay, contamination,putrification
3:The presence of bacteria in blood that ate ectively multiplying (Serious)
Define ASEPSIS - answers-A medical tem, any procedure that prevents the
entrance of infectious agents into sterile tissue, thus preventing infection.
