LAB 3 NURUL SAFFA BINTI ZAINAL ABIDIN
PREPARATION AND STERILIZATION
OF CULTURE MEDIA
INTRODUCTION :
A microbial culture is a method of multiplying microbial organisms
by letting them reproduce in predetermined culture media under controlled
laboratory conditions.
Bacteria are microorganisms that grow everywhere. We can collect and
grow them in specially prepared petri dish. Bloods agar ot tryptic soy agar
with sheep’s blood is an excellent medium for supplying bacteria with nutrients
and an environment in which we can see them grow.
Sterile powdered agar with nutrients can be mixed with water, heated
and then poured into empty petri dish. The undigestible agar is a gelatin-like
substances with a semi solid surface on which the bacteria can grow while they
consume the added nutrients ( like sheep’s blood).
The broth contains : 0.6 g/L “lab-lamco” (beef extract)
0.4 g/L yeast
extract
1.0 g/L
peptone ( a nitrogen sources)
1.0 g/L
sodium chloride
3.0 g/L agar
powder
An autoclaves is perhaps,one of the most important devices in the
medical field. An autoclave heats sterilizing solutions above their boiling point
to sterilize medical or laboratory instruments. The autoclave also used in
industry to “cure” some products during the manufacturing process. An autoclave
is an instrument used to sterilize equipmemt and supplies by subjecting them to
high pressure under saturated steam at 121 degree celcius for around 15-20 minutes
depending on the size of the load and the contents.
The autoclave comes in several types. One of the simplest
autoclaves looks a great deal like pressure cooker. It is large pot with gauge
on top and bolts that fasten the top to the pot. The idea behind this is that
water inside a pressurized container can be heated above the boiling point. It will
only reach 212 degree Fahrenheit (100 celcius) in an open container. However in
a pressurized autoclaved, the water will reach much higher tempereatures.
OBJECTIVES :
OBJECTIVES :
To prepare sterile nutrients agar for culturing microorganisms
DISCUSSIONS :
Microbiological cultures can be grown in petri dish of differing
that have a thin layer of agar-based growth medium. Once the growth medium in
the petri dish is inoculated with the desired bacteria, the plates are
incubated at the best temperature for the growing of the selected bacteria.
Microbial culture are foundational and basic diagnostic methods
used extensively as an research tool in molecular biology. It is often essential to isolate a
pure culture of microorganisms. A pure culture is a population of cells or
multicellular organisms growing in the absence of other species or types. A pure
culture may originate from a single cell or single organism, in which case the
cells are genetic clones of one another.
For the purpose of gelling the microbial culture, the medium of
agarose (agar) is used. Agar is a gelantinous substance derived from seaweed. A
cheap substitute for agar is guar gum, which can be used for the isolation and
maintenance of thermophiles.
In this experiment,after weigh appropriate amount of broth (with
agar) powder into Scott bottles and dissolve with distilled water, make sure it
mix wellthen loosely recap the bottles and set aside for sterilization process.
Sterilize using an autoclave at 121 degree celcius for 15 minutes.
REFRENCES :
Pearson international edition 8th edition campbell
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