Learning Intention: To become familiar with Aseptic Technique and to use it to plate bacterial cultures.

Success Criteria:1. I can organise my work area in a safe

manner taking into consideration the requirements for sterility.

2. I can open and close bacterial culture tubes without putting the lid down on the bench.

3. I can plate bacteria onto the agar without damaging the agar.

4. I can apply the mastring5. I am confident using Aseptic Technique

Explicit Vocabulary

Mastring Impregnated Reconstitute Plate (microbiological definition) Flame (microbiological definition) Nutrient agar Aseptic Incubation

ASEPTIC TECHNIQUE

Aseptic technique refers to a procedure that is performed under sterile conditions. This includes medical and laboratory techniques which deal with cultures and human cells and tissue for transplantation. The largest example of aseptic techniques is in hospital operating theatres. It is used to stop the spread of infection.

Types of Aseptic Techniques

Flame sterilization - metal loops used for picking up cultures , forceps and the necks of glass/plastic reciprocals are flamed to prevent microbial contamination.

Reducing the time in which microbial samples and sterilised instruments have contact with the air

The use of an autoclave or pressure cooker to sterilise growth media and broths and also non-metal/ glass instruments such as plastic spreaders etc.

Ensuring your work space and yourself is cleaned with appropriate cleaning substances and disinfectants.

The main aim is to prevent the contamination from you to your environment and from the environment to you and therefore the possible spread of the contaminant outside of the laboratory.

Flaming using the Bunsen Burner

Laminar Flow Cabinets

Horizontal laminar flow cabinets pass the filtered air across the work and out into the room.

Aseptic Steps for Practical 1. Work in groups of three. Each person

plates a different bacteria. 2. Collect equipment: laboratory coat,

gloves, bunsen burner, matches, swabs x3, disinfectant, disposable, 3 nutrient agar plates, marker, masking tape, mastring, bacterial cultures to be shared amongst class, beaker containing disinfectant for used swabs, forceps.

3. Disinfect your work area- working from back to front.

4. Arrange equipment as shown in demonstration.

5. light Bunsen Burner and flame the top of the bacterial culture tube. Remember to hold the cap in your little finger. Do not put it down on the bench.

6. Insert the swab and soak up some of the bacterial broth culture.

7. Remove and reseal the tube with the lid. 8. Still holding the swab, open the petri dish

and very gently spread the bacteria over the nutrient agar as demonstrated.

9. Close the petri dish lid and place the infected swab into the beaker containing disinfectant.

10. Flame the forceps and carefully pick up a mastring at the white tab part only.

MASTRING

C- ChloramphenicolPG- Penicilin GS – SulphatriadSt - StreptomycinT - TetracyclineAp – Ampicillin

11. Ensure all the disks are in contact with the agar by gently tapping only the white spaces on the disc.

12. Close the petri dish lid. 13. Flame the forceps. 14 Label the petri dish with your initials, the

name of the bacteria, incubation time (48hrs), incubation temperature (30o), and date.

15. Seal plate with masking tape. 16. Place all plates at the front of the class. 17. pack away equipment. 18. Disinfectant your work area. 19. Wash your hands with soap and water.

BACTERIAL CULTURES

E Coli –Escherichia coliStaph Albus - Staphylococcus

albusB Subtilis -Bacillius subtilis

Scientific Nomenclature of Bacterial Names

Nomenclature of bacteria refers to naming bacteria and other organisms according to the binomial system, which was introduced by Carl Linnaeus (1674-1748).

A bacterium has a species name, composed of a genus name that tells you to which genus it belongs and a species epithet which, together with the genus name, is unique to the bacterium.

An example is Moraxella bovis, where the genus name indicates that the bacterium belongs to the genus Moraxella and the species name indicates that the bacterium has been isolated from cattle.

The genus name and the species epithet form the scientific name of the species, which is always written in italics, with a capital letter starting the Genus name only. The species name is always written in lower case.

Questions 1. What is a control and what is it used for? 2. Why are the cultures incubated at 30o and not 37o? 3. Why is it important not to touch the coloured discs? 4. What is the purpose of flaming the culture tube before and after insertion of the swab? 5. Why should there be minimal talking and moving around whilst performing this experiment? 6. Describe how the plates should be disposed of and why?

Review- 3 things I have learnt today……….

- 2 new words I can add to my Biology vocabulary list and there meaning……………………

- My understanding of aseptic technique is …….