The document presents an overview of pure culture techniques used in microbiology, including methods like streak plate, pour plate, and spread plate techniques, which are essential for isolating and multiplying microbial organisms. It explains the importance of aseptic techniques to prevent contamination and the role of various culture media in obtaining pure cultures. The presentation emphasizes that not all microorganisms are harmful, highlighting the significance of understanding both beneficial and harmful microbes.

1. A presentation on
Pure culture technique

2. Microbial culture
A microbiological culture, or microbial culture, is a method of
multiplying microbial organisms by letting them reproduce in
predetermined culture medium under controlled laboratory
conditions. Microbial cultures are foundational and basic
diagnostic methods used extensively as a research tool in
molecular biology.

3. Culture media
•The Preservation Culture Media
•The Enrichment Culture Media
•Selective Culture Media
•Differential Culture Media
•General Purpose Media
•Isolation Culture Media

4. A pure (or axenic) culture is a population of cells
or multicellularorganisms 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.
Pure culture

5. Streak plate technique
Pure culture technique
 streak plate technique
 Pour plate technique
 Spread plate technique
 Serial dialution method
Culture’sapparetus
Agar plate Inoculating loop
flame Bacterial source
LAF

6. Aseptictechnique
This method of preventing unwanted microorganisms from gaining
access is termed aseptic technique.
The best way to obtain a pure culture is to start with a single bacterial
cell.
A single unwanted contaminant cell can do the same thing in an
otherwise pure culture, making the culture useless.
The most commonly used device for moving bacteria is the inoculating
loop.
This is simply a piece of nichrome or platinum
wire with a loop at one end and a handle at the other.

7. Streak plate method
Flame the inoculating loop untill the wire glows red.
Allow the loop to cool and get a loopful of the suspension of solution
Pick up your plate and streak the surface, flame the loop before
streaking next section. When streaking, be care not cut into agar and
not to be far away from flame.

8. Each time turn the plate
45 degree
Cultured view
Streak plate method
(in pictures)

9. Pour plate method
•1 ml of appropriately diluted inoculum is added to 15 ml of molten agar and
poured on petridish.
•Colonies appear through out the depth of medium.
•Used to estimate viable count, recommended method for quantitative urine
cultures

10. Pour plate method
(Inpictures)
Cultured view

11. Spread plate technique
In this technique culture is not mixed with agar medium. Instead mixed with normal
saline.
0.1 ml sample taken from diluted sample and placed on the surface of agar plate and
spread over the surface by L shaped glass rod.
Incubate the plate.
After incubation ,colonies are observed on agar surface

12. Spreadplate technique
In pictures

13. Serial dialution method
Determine the proper dilution liquid. The liquid that will be diluting our substance in is
very important.
Prepare several test tubes with 9 mL of dilution liquid. These tubes will serve as your
dilution blanks.
Prepare a test tube with at least 2 mL of your undiluted solution. The minimum amount
needed to perform this serial dilution is 1 mL of undiluted solution.
Perform the first dilution. Draw 1 mL of undiluted solution from test tube US with a pipette
and transfer it to the test tube labeled 1:10 containing 9 mL of the dilution liquid and mix
thoroughly.
Extend this procedure to perform longer serial dilutions. a serial dilution to create a series
of solutions with dilutions of 1, 1:10, 1:100, 1:1,000.

14. Step:1 Step:2
Step:3
Step:4
Step:5
Step :6 calculation
Serial dialutionmethod

16. Thank you for
listening

17. All microorganisams are not bad, some
are also good