Basic Microbiological Techniques
Ozan Enver Özdemir
Submission Date and Section
Aim of this first experiment is producing individual E.Colibakteria colonies with using streaking method .Aim of second experiment is planting with using spreading method and with serial dilution to observe the decreasing number of colonies. 2.Theory
Some micro-organisms can be harmful to humans as they cause illness. For this reason, microbiological techniques have been developed to control the unwanted growth and spreading of micro-organisms.We try to learn about micro-organisms and understand that how do micro-organisms grow in human body using microbiological techniques.
In this experiment we use some microbiological techniques. First of all is Culturing :
A sample (called the inoculum)(E.Colibakteria) is introduced into a culture medium that provides an controlled environment where the micro-organism can multiply. The observable growth that appears in the medium is known as a culturing.
Microbiological media is a medium which inculudes all requirements for growth of microorganisms. there are organic and inorganic compounds.2 types of medias use in laboratory.Nutrient Broth(liquid, contained in bottle or tubes.) and other one is Nutrient Agar(solid, actually like jelly, contained in petri dishes.)
We use one of the culture as known Pure Calture ; is culture that contains a single known species or type of micro-organism. This type of culture is most constantly used for the study of micro-organisms in the laboratory.
When studying the single type of a micro-organism(pure calture) other micro-organisms must not introduce our culture . Otherwise we will not take certain results(Contaminating). Contaminating micro-organisms may produce substances that can prevent the growth of the studied micro-organism.
Streaking is one of the microbiological techniques is used for that increase the chance for producing individual colonies from individual microbial cells which seperated by dragging over the surface of agar. This method is used for that isolate the cells from crowded colonies to reproduce them in controlled environment.There are several types of streaking method.
PICTURE:T-1 types of streaking method
Serial dilution is frequently used in laboratary to lessen number of microorganism per unit of sample before using spreading method . spreading method is useful for planting and isolating individual cells from crowded colonies to obvious observation. 3.Materials and Chemicals
Culture of Bacteria
MicrocetrifugeTube(Eppendorf Tube) 1.5ml
Culture of Bacteria
The cap of tube contains culture of bacteria was opened . The loop was put into the tube. The cap was closed. The lid of the Petri dish to be streaked at nearly 45-degree angle was lifted.Four areas were determineted on the dish imaginery. The loop was placed into dish.The loop was touched the medium. One of the areas was streaked in s-shape from back to front and single inoculation area was made then culture was thinned by dragging bacterias from initial area to other 3 areas, decreasing bacteria population.For each areas the loop was changed.
PİCTURE :E-1 streaking method on agar
Five petri dish was prepared for planting. Firstly 900 microlitres Nutrient broth(NB)was poured each microcentrifugetubes.100 microlitres stock was taken and added first microcentrifugetubes and solution was shaken(it must be homogenized ).Then poured first petri dish and then glass rod was dipped into alcohol burner,then burned and cooled . The bacteria was planted using spreading method addition to...