Techniques and Methods of Sterilization in Microbiology

Joko Warino S.P M.Si

Techniques and Methods of Sterilization in Microbiology

Microbiology is a field of study that focuses on microscopic living organisms or microbes. Research in microbiology plays a crucial role in the medical world as it functions in the effort to address diseases.

Harmful microorganisms that have the potential to cause diseases are referred to as pathogens.

The scope of microbiology encompasses the study of pathogens and the endeavor to develop strategies to combat and prevent infections.

Scientists have successfully developed antibodies and vaccines used to treat and prevent diseases caused by various forms of weak microbes.

Moreover, several important microorganisms have also been created to support digestive processes and the production of products like cheese and yogurt.

In the environment of a microbiology laboratory, aseptic techniques are applied with the aim of preventing microbiological contamination.

Furthermore, aseptic techniques are also valuable in preventing room contamination and safeguarding personnel from microorganism exposure.

Microorganisms present within the laboratory environment include pathogens; hence, the utilization of aseptic techniques becomes essential to ensure the safety of laboratory personnel.

One fundamental technique in microbiological analysis is aseptic technique. Aseptic technique is a method or approach used to transfer bacterial cultures from one place to another in a clean manner, with the aim of preventing contamination from other microorganisms into the culture.

Moreover, the application of aseptic techniques during sample collection offers the benefit of preventing contamination.

The same principle applies to the equipment used, which must be in a sterilized condition. When collecting liquid food items, using a sterile pipette is recommended.

Meanwhile, for solid food, the collection process can involve the use of sterilized knives, forks, spoons, or clamps.

Aseptic technique becomes exceptionally crucial in averting contaminating microorganisms that could impede the growth of desired microbes.

The use of aseptic techniques is employed throughout activities, both with equipment and materials, as well as within the surrounding environment and during practical implementation. Sterilization is the method used to ensure the cleanliness of laboratory equipment and materials.

Instruments to be used in research or practical experiments must be sterilized beforehand.

This sterilization process aims to eliminate all forms of life from the materials and equipment.

In another context, sterilization is a measure to extinguish all types of organisms present on an object.

In the domain of microbiology, sterilization refers to the effort of eradicating all forms of life from objects or substances, regardless of their forms. This process can involve the killing of microorganisms through heat or high temperatures, the use of gases such as formaldehyde, ethylene oxide, or beta-propiolactone, as well as various types of chemical solutions or even exposure to ultraviolet or gamma rays.

Techniques and Methods of Sterilization in Microbiology

Techniques and Methods of Sterilization in Microbiology

Within the methodology of Sterilization in Microbiology, there are three distinct approaches: mechanical, physical, and chemical.

1. Mechanical Sterilization (Filtration)

This involves the use of filters with very small pores, usually around 0.22 microns or 0.45 microns in size.

With such tiny pores, microbes can be trapped within the filter.

This process is commonly applied to sterilize heat-resistant materials, such as enzyme solutions and antibiotics.

2. Physical Sterilization

This approach involves heating and irradiation and can be divided into several stages:

  • Direct Heating: Instruments like inoculum needles, L-shaped rods, and forceps can be sterilized by directly exposing them to flame.
  • Dry Heat: Sterilization using an oven at temperatures around 60 – 180°C. Dry heat techniques are suitable for glassware items like Erlenmeyer flasks and test tubes.
  • Steam Heat: Sterilization by steaming the instruments.
  • Pressurized Steam: Sterilization using an autoclave.

This technique involves the use of chemicals, such as ethylene oxide gas, to kill microorganisms.

Efforts towards sterilization can also be realized through the use of ultraviolet (UV) radiation.

For instance, UV lamps can be employed to eliminate microorganisms adhering to the surface of an Interior Safety Cabinet.

3. Sterilization via Chemical Approach

Commonly, this sterilization technique involves the use of disinfectants like alcohol.

That concludes the presentation on Methods and Practices of Sterilization in Microbiology. May this information prove beneficial.



Joko Warino S.P M.Si

Allow me to introduce myself, my name is Joko Warino, a lecturer at one of the universities in Indonesia (Faculty of Agriculture and Animal Husbandry, UIN Suska Riau Indonesia). My field of expertise is soil science.

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