Define and classify moist heat sterilisation with examples

Hello there,

Moist Heat sterilization is a technique used to sterilize a surface or object using hot water vapors as sterilizing agent.

This destroys the micro-organisms by destroying the macro-molecules especially proteins.

The methods used for moist sterilization are :

1. Tyndallization: It is the sterilization process done in three steps of steam treatment over three days.

2. High pressure  treatment : The sample is placed in a high temperature and high pressure vessel for 15-20 min which is enough for the sterilization.

Hope that i have answered your query..

Good Luck !!!

1. Temperature below 100 C Example:  Pasteurisation ; Pasteurised milk.
2. Temperature at 100C Example:Tyndallisation
3. Steam Under Pressure. Example : Autoclave

Hi Aspirant,

What is moist heat sterlization?

Moist heat sterlization describes sterlization eating an article is one of the earliest forms of sterilization practiced. The various procedures used to perform moist heat sterilization process cause destruction of micro-organisms by denaturationof macromolecules.

Moist heat causes destruction of micro- organisms by denaturation of macromolecules, primarily proteins. Autoclaving (pressure cooking) is a very common method for moist sterilization. It is effective in killing fungi, bacteria, spores, and viruses but does not necessarily eliminate prions. When sterilizing in this way, samples are placed into a steam chamber. The chamber is closed and heated so that steam forces air out of the vents or exhausts. Pressure is then applied so that the interior temperature reaches 121°C. This temperature is maintained for between 15 and 30 minutes. This elevated temperature and pressure is sufficient to sterilize samples of any commonly encountered microbes or spores. The chamber is then allowed to cool slowly or by passive heat dissipation.

Pressure sterilization is the prevailing method used for medical sterilization of heat-resistant tools. It is also used for sterilization of materials for microbiology and other fields calling for aseptic technique. To facilitate efficient sterilization by steam and pressure, there are several methods of verification and indication used; these include color-changing indicator tapes and biological indicators. For any method of moist heat sterilization, it is common to use biological indicators as a means of validation and confirmation. When using biological indicators, samples containing spores of heat-resistant microbes such as Geobacillus stearothermophilis are sterilized alongside a standard load, and are then incubated in sterile media (often contained within the sample in a glass ampoule to be broken after sterilization). A color change in the media (indicating acid production by bacteria; requires the medium to be formulated for this purpose) or the appearance of turbidity (cloudiness indicating light scattering by bacterial cells) indicates that sterilization was not achieved and the sterilization cycle may need revision or improvement. Other moist methods are boiling samples for certain period of time and Tyndallisation. Boiling is not efficient in eliminating spores. Tyndallisation inactivates spores as well, but is a more lengthy process.

Moist heat sterilization using autoclave is commonly used for the sterilization of biohazardous trash, heat and moisture resistant materials such as aqueous preparation (culture media).  This method is also used for the sterilization of surgical dressings and medical devices.

Hey student,

Moist heat sterilization describes sterilization techniques that use hot water vapor as a sterilizing agent. This type of sterilization involves lower temperature and high-pressure of water (steam).

Advantages:

• Requires low temperature
• Less time to complete
• Easy to control and monitor
• Low cost, non-toxic

Disadvantages:

• The heat-sensitive instrument cannot be sterilized
• After sterilization, the instrument remains wet, which may lead to rust
• Chances of getting instrument damaged, due to repeated exposure

Methods Used:

• Tyndallization
• High Pressure

Based on temperature there are two types of Moist Heat Sterilization:

• Temp below 100 degree Celsius
• Temp at 100 degree Celsius

Hope it helps!

Dear Student

Moist heat sterilization describes sterilization techniques that use hot water vapor as a sterilizing agent. ... The various procedures used to perform moist heat sterilization process cause destruction of micro-organisms by denaturation of macromolecules.

Moist heat destroys microorganisms by the irreversible denaturation of enzymes and structural proteins. The temperature at which denaturation occurs varies inversely with the amount of water present. Sterilization in saturated steam thus requires precise control of time, temperature, and pressure.

Hope it helps