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What is Sterilization?

Sterilization is a process of destroying all germs including persistent microorganisms and bacterias. The whole process is difficult to achieve because chemicals are not always able to kill unwanted or hazardous leftovers.


Methods to Kill Bacteria?

There are many methods to kill the microorganisms including Ultraviolet and ionizing radiations, altering DNA to hinder any replication. However Ultraviolet sterilization always does not provide the most effective outcomes or ease of validation as moist heat (steam) sterilization.


Microorganisms and temperature correlate with each other. As temperature rises the microorganisms become active but still do not completely die. The temperature and time required to deactivate Prions are significantly higher.


In order to destroy microbes, steam molecules are being condensed and then transferred in 2500 joules per gram effectively heating the microbes to completely destroy them.


There are other methods to destroy the microorganisms which include low heat conditions and boundary layer effects, which can insulate and protect microorganisms.


For maximum optimum, the Steam method is used where the temperature is high and pressure can be monitored giving for verification of sterilization. High levels of sterilization can be achieved by using Steam Sterilization procedures, and the steam sterilizer or autoclave is the most common piece of equipment used in laboratories and hospitals.


In labs, a wide range of microbes exist and therefore a wide range of sterilization of this micro activity is required for controlling and balancing the environment.


The basic aim of the process of sterilization is complete destruction of microbes that are undesired in order to maintain a clean environment. This can be achieved by a variety of procedures each with its positive and negative aspects.


The ideal sterilizing technique should deactivate microbiological and undesired biological material such as prions rapidly and effectively. It should provide a less toxic environment, conclude fewer health risk operators and transition to sterile objects, all while allowing for maximum adaptability while accommodating a variety of materials. The goal of the process is to remove any physical difficulties in sterilization and achieve this in a cost-effective way. Meeting all of these requirements, on the other hand, is frequently impossible. As a result, including many of these elements is frequently a secondary issue, with the primary goal being to achieve asepsis in a functional end product.


Methods of Sterilization 

  1. Sterile Filtration - Filtration is an option to consider if a fluid material needs to be sterilized. A liquid or gas can pass through a sterilizing filter membrane, which creates a mechanical barrier to all particles larger than the membrane's pores. Larger microorganisms are retained behind the filter, ensuring that they do not enter the filtrate. Filtration, on the other hand, has no such consequences, as it only removes particles larger than a specific size. As a result, filtering is a viable option for highly volatile and reactive fluids.

  2. Disinfection - Most pathogens are eliminated, but not all types of bacteria are. Microbial contamination is reduced through disinfection. Unlike chemical sterilization, chemical disinfection does not kill spores. Freshly produced 10% bleach and 70% ethanol are two often used laboratory disinfectants. High-level disinfection consists of a high percentage of chemicals effectively killing vegetative microorganisms. The intermediate approach kills viruses but not as effectively whereas the low level kills only some inactive viruses.  

  3. Heat Radiation - UV rays are not very effective on light opaque material. Microorganisms which are protected by dust and UV are ineffective. The collection of dust and grime on the bulb surface affects UV light. These technologies sterilize by causing free radicals to be released by electromagnetically stimulating particles in the sterilized area. Radiation sterilants can destroy organic compounds due to their functionality.

  4. Chemical Method - Chemical sterilization alters the physical dynamics of molecules within a microbe to alter the structural dimensions. Because gamma and X-rays are highly penetrative, they can be utilized to sterilize things contained in otherwise impenetrable enclosures. The highlight of electron beam sterilization is the ability to sanitize almost instantly.

  5. Antisepsis - It includes the use of liquid antimicrobial agents to kill germs. It entails swabbing a person's or animal's injection site and handwashing with germicidal treatments.

  6. Cleaning - Decontamination is the process of making something or something safe to handle. The degree of microbial contamination has been lowered to the point where there is no possibility of infection transmission. Decontamination includes sterilization, disinfection, and antisepsis.


A sterilization cycle's effectiveness can be influenced by a number of factors like  Temperature, relative humidity, pH, and exposure time are all aspects to consider. Because there are so many variables, an industry-wide approach for determining a connection between a defined set of parameters during a specific exposure time is required. If all other factors remain constant, the higher the number of germs, the longer it will take a germicide to kill them completely. When evaluating factors affecting the efficacy of germicides, the location of microorganisms should be evaluated.

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FAQs on Sterilization

1. Can sterilization methods kill viruses?

Yes, sterilization methods have the ability to kill all viruses. These methods can also kill life forms, even transmissible agents such as bacteria, viruses, spore forms and fungi. Because of this reason, sterilised objects which we use are fully safe. Methods which we use during the sterilization process include heating, hydrogen peroxide gas, radiation, ethylene oxide gas etc.

2. Name a few food products which are being sterilized using radiation?

Some of the common food products which are being sterilised using radiations are:

Beef and Pork.

Crustaceans (e.g., lobster, shrimp, and crab)

Fresh Fruits and Vegetables.

Lettuce and Spinach.

Poultry.

Seeds for Sprouting

3. Define the term sterilization?

It is a kind of process which is being used to kill all types of microorganisms including its spores. We use this process to maintain a sterile environment around us. The sterilization process is mainly done by giving heat, irradiation, filtration, high pressure etc.


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