The ingredient added to make solid or semi solid media is:
Agar
Agar will not go into solution until the media have been:
Heated
Synthetic Medium
All of the ingredients are known
Complex Medium
1 or more of the ingredients is unknown
Name 3 constituents or ingredients of media which are required for bacterial growth:
Water, Nutrients, Growth Factors
Autoclaving Temperature is:
121 degrees Celsius
Autoclaving Time is:
15 Minutes
Autoclaving Pressure is:
15 lbs/sq. in
At what temperature does agar solidify after it has been dissolved?
45 degrees Celsius
Broths
Used to Propogate
Slants:
- Short-Term storage
- Increases the surface area, will make nutrients last longer
Plates:
- Isolation
- Will give rise to colonies
Agar:
Complex polysaccaride, cannot be used as a source of nutrients
Broth %
0%
Semi-Solid Media %
0.4-0.6%
Solid Media
1-2%
Unknown Composition
Rich/Complex/Undefined
Known Composition
Defined Media
4 Quadrant Streak:
- Reduce amoculate in each quadrant
- Clockwise
Selective Media
- Only grows what is selected and stops growing anything else
- DONT want G+
What position should the plates be incubated in?
Inverted position
Why is the loop flamed?
To sterilize it
True or False: It is okay to remove a lid from a tube and place it on the counter while inoculating the tube?
False
The purpose of the streak plate technique is to obtain __________ colonies?
Isolated
Slants are used for ________ - _____ _______ of cultures.
Short-Term storage
______ tubes are used for propagation of cultures.
Broth
Pure Culture:
Only 1 stain or colony is present
What is the purpose of aseptic technique?
To reduce or remove the number of microbes
Selective Media:
Used to isolate particular groups of organisms while inhabiting others
Differential Media:
Allow differentiation of colonies of desired organisms that grow on the same plate
MacConkey Agar is selective for _____ bacteria and differential on _______ fermentation.
G - ; Lactose
CNA is selective for ___ bacteria.
G +
What is the purpose of blood agar plates?
To observe the hemolytic activity of some bacteria and to grow fastidious organisms.
*** Not all bacteria grow on blood agar are fastidious
CNA Agar:
SELECTIVE Media
Organisms = G+
Inhibitor = CNA
Indicator = N/A
Results = Growth of G+ organisms
Mannitol Salt Agar
Both SELECTIVE & DIFFERENTIAL Media
Organisms = Staphylococcus Spp
Inhibitor = NaCl
Indicator = Phenol Red
Results = S. saprophyticus produces white colonies and turns media yellow
S. epidermis grows but does not ferment mannitol
Blood Agar
Differential Media
Organisms = G+ & G-
Inhibitor = N/A
Indicator = Blood
Results = Hemolytic patterns
MacConkey Agar
Both SELECTIVE AND DIFFERENTIAL
Organisms = G-
Inhibitor = Bile Salts
Indicator = Neutral Red
Results = Lactose fermenting
Tryptic Soy Agar
GENERAL Media
Organisms = G+ & G-
Inhibitor = N/A
Indicator = N/A
Results = used in 2042 labs
Negative Stain
o Add nigrosin to plate
o Add bacteria
o Place another slide at a 45 angle
o Drag slide across, spreading the solution
o Air dry
Simple Stain
o Prepare smear of bacteria
o Stain it with methylene blue for one minute
o Wash gently with water
o Blot dry with bibulous paper