BACTERIAL CULTIVATION TECHNIQUES: Manual Flashcards
Bacteria are microscopic organisms.
However, when mass multiplication occurs, bacteria can be seen macroscopically, as seen in_____
culture or in colony
different techniques of______ or simply the planting or more appropriately the seeding of a sample suspiciously harboring bacteria.
This is called______.
inoculation
cultivation
Culture Transfer Techniques
In several microbiology experiments, you will need to transfer microorganisms from one medium to another by_______.
This aseptic technique also is commonly used when preparing and maintaining stock cultures, and when carrying out a number of microbiological test procedures.
subculturing
refers to the process of transferring microorganisms from one growth medium to another to maintain or grow the bacterial culture.
This technique helps to keep the bacteria alive, isolate a specific species, or increase the amount of bacteria available for further study.
It’s an essential step in microbiology to ensure that cultures remain pure and uncontaminated.
subculturing
_________are everywhere, including in the air of your course lab, as well as on the floors, bench tops, and equipment.
If appropriate precautions are not taken, these microbes could end up in one of your_______; that is, microbes could contaminate your materials.
Microorganisms
subcultures
To prevent contamination by unwanted microbes, the microbes you want must be transferred using proper________.
aseptic techniques
are a set of practices used in microbiology, medicine, and laboratory work to prevent contamination by unwanted microorganisms.
These techniques are crucial for maintaining sterile conditions, especially when handling cultures, performing surgeries, or administering injections.
Aseptic techniques
Aseptic transfer techniques are not difficult to learn and perform, although some eye-hand coordination and practice may be needed.
To simplify the process:
make sure all needed materials, cultures, and media are ready
and the wire of the transferring device (inoculating loop or needle is straight).
Label appropriately all_____ into which microbes will be transferred so you can identify your cultures during the lab period, or if incubated, when the next lab period meets.
media
Aseptic transfer
(a) Heat wire loop until red hot then cool in air briefly
(b) Uncap culture tube
(c) Heat the mouth of the tube
(d) With the loop, gather the inoculum
(e) Reheat the mouth of the tube
(f) Recap the tube.
After gathering the inoculum, the inoculum may be transferred into a…
tubed media (A) or plated media (B)
Stab techniques for tubed media
The semi-solid media is stabbed about……
Technique for streaking the surface of an _____using a wire loop.
2/3 its depth with the wire needle without touching the walls and the bottom of the tube.
agar slant
Quadrant streaking technique
Aseptically obtain culture
Streak in 1st quadrant
FLAME LOOP
Streak into 2nd quadrant by pulling through area in FIRST quadrant 2 times
FLAME LOOP
Streak into 3nd quadrant by pulling through area in SECOND quadrant 2 times
FLAME LOOP
Streak into 4 quadrant by pulling through area in THIRD quadrant
Label the bottom side of a nutrient agar plate with your……..
Obtain a loopful of bacterial broth culture. Before beginning the streak plate technique, read the instruction thoroughly to familiarize yourself with the technique.
name
the date
the designation “BC-SP” for bacterial culture-streak plate
Aseptically obtain a loopful of the bacterial culture, and lightly streak it several times along one area (quadrant) of the plate
Try not to_____ into the agar surface and avoid_______ by lifting the lid of the Petri dish only enough to permit entry of the loop. Replace the lid.
cut
airborne contamination
_____all the plates and incubate them for______ at the appropriate temperature.
The plates are inverted so that moisture accumulates on the lid rather than on the agar surface, where it may cause colonies to run together.
After incubation, refrigerate the plates in the inverted position until the next laboratory session to preserve the bacterial growth and prevent drying of the medium.
Invert; 24-48 hours
Examine the plates for well-isolated and separated colonies.
Draw a representation of a good streak plate in the Results/Lab Report section.
Add appropriate labels.
Describe several isolated colonies by_____ the colonies and noting their (3), with reference to the standard terminology.
The size of a colony may be determined by measuring the colony diameter in______ if rulers are available.
Record your observations.
numbering
size, color, and characteristics
millimeters
At the direction of the instructor, use a_________ to select samples from various colonies, and inoculate nutrient agar slants to obtain pure cultures.
Note: Never touch the bacterial colonies on a plate with your fingers. Each colony contains millions of live organisms.
inoculating needle or loop
Unkown sample
Label
“RS-SP” Random surface-streak plate
Morphologic Characteristics of Bacterial Colonies
Shape
Size
Surface
Color
Opacity
Elevation
Margin
Shape
circular
punctiform
filamentous
irregular
rhizoid
Size
Small
Medium
Large
surface
smooth
glistening
rough
wrinkle
dull
color
white
creamy-white
yellow
orange
green
opacity
transparent
translucent
opaque
elevation
flat
umbonate
raised
convex
pulvinate
margin
even
wavy
filamentous
lobate
curled
