5 common laboratory sterilization methods


Sterilization is necessary in all laboratories and hospitals. This is because viruses, bacteria, fungi and other pathogens cannot be completely killed by disinfection. All disinfection can do is remove dirt and bacteria in the same way we remove them from the kitchen. It only removes these agents, but does not kill or eliminate them. Procedures such as decontamination and sterilization of laboratory equipment also contribute to health and safety. Sterilization is essential to keep laboratory equipment, materials and samples clean and functional.

1. Humid heat (autoclave)

Autoclave is the most popular laboratory sterilization method. The process uses pressurized steam to heat items that need to be sterilized. Autoclaving is a very effective procedure. It will effectively kill all microorganisms, spores and viruses. However, higher vapor temperatures or longer incubation periods are required for certain biosafety levels.

Steam sterilization distributes heat over the entire surface. This method instantly kills and eliminates stubborn bacteria, fungi and pathogens. It is also a proven method for cleaning hospital and laboratory equipment of all sizes and shapes.

The speed and efficiency with which autoclaves sterilize materials make them the most popular choice.

2. Dry heat (baking or flame)

Dry heat sterilization is applicable to blast drying oven for sterilization of glass and metal products with high temperature resistance, grease (such as oily ointment mechanism, injection oil, etc.) and powder chemicals with high temperature resistance that cannot be penetrated by damp and hot gas. In the dry hot state, due to the poor thermal penetration, the microorganism has a strong heat resistance, and must be subjected to high temperature for a long time to achieve the purpose of sterilization. The main difference between dry heat and autoclave is the absence of water or steam in dry heat.

The advantages of dry heat include: non-toxic, does not harm the environment; The dry hot cabinet is easy to install, and the operation cost is relatively low. It penetrates materials: non-corrosive to metals and sharp instruments.

The disadvantage of dry heat is that the heat penetration rate is slow, and sterilization makes it a time-consuming method. In addition, high temperatures are not suitable for most materials.

3. The filter

Filtration is a laboratory sterilization method that does not require heating. In addition, it is the only sterilization method that relies on force to separate microorganisms or bacteria from the liquid rather than killing them. The function of a filter is to pass a liquid solution through a filter whose pore size is too small for microorganisms to pass through. Essentially, the filter removes the organism from the solution.

For proper disinfection, the filters used are usually membrane filters made of cellulose esters. To remove bacteria, they typically have an average pore size of 0.2um. However, if viruses or phages are a problem, filters are not a good sterilization technique. These organisms can usually pass through the finest filters.

4. Chemicals/solvents

To disinfect them without using heat, the recommended alternative is chemical disinfection. Chemical sterilization is the process of using cryogenic chemicals to kill, eliminate and remove all bacteria, viruses and bacteria. This can be in the form of gas or liquid chemicals.

Although the chemicals used for disinfection are harmful to humans, they do not damage items that must be disinfected. Even gases are solvents that can sterilize objects. They provide rapid sterilization by rapidly permeating the material without using accelerated heating.

Hydrogen peroxide, nitrogen dioxide and formaldehyde solutions are some of the most common chemical disinfectants. While these solvents are excellent at killing microbial cells, they have no effect on spores.

5. Radiation

Radiation use can be an excellent technique for laboratory sterilization. Ultraviolet, X-ray and gamma rays are types of electromagnetic radiation that can quickly shatter DNA. Ultraviolet light has limited air penetration, so disinfection occurs only in a fairly small area around the lamp. However, it is relatively safe and useful for disinfecting small areas such as laminar flow hoods. While this makes them inherently more dangerous, it also means they can be effectively sterilized on a larger scale.

You can choose from many different types of steam sterilizers. The most important factor in choosing the right machine often depends on the number and type of tools you need to work with. We will offer you autoclaves with many different types, regardless of brand, to further improve the efficiency of your steam sterilizer and provide 100% clean steam.

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