Sterilization is the complete destruction or removal of all microorganisms, including bacteria, spores, and viruses.
Used in labs, medicine, and food processing to make surfaces, tools, and products microbe-free.
| Method | Description | Example Use |
|---|---|---|
| Autoclaving | Steam under pressure (121°C, 15 min) | Lab glassware, surgical tools |
| Dry Heat | Oven heating at 160–180°C | Metal tools |
| Chemical Sterilizers | Use of bleach or alcohol | Surfaces, skin disinfection |
| Radiation | UV/gamma rays kill DNA | Medical and food packaging |
| Filtration | Microbe removal from liquids/gases | Antibiotic or vaccine production |
Pasteurization is partial sterilization using mild heat to kill harmful microbes without destroying quality.
Not all microbes are killed — just enough to make food/drinks safe and increase shelf life.
| Process | Temperature Used | Purpose |
|---|---|---|
| Sterilization | Very high (121°C in autoclaves) | Kills all microbes (including spores) |
| Pasteurization | Moderate (e.g. 72°C for 15 sec) | Kills harmful microbes, preserves nutrients |
Developed by Louis Pasteur
Common in:
📌 Pasteurization does NOT kill all microbes, so pasteurized products still need refrigeration.
Aseptic techniques are practices used to prevent contamination by unwanted microbes.
Ensures clean environments in labs, hospitals, and food factories.
| Technique | Purpose |
|---|---|
| Wearing gloves/masks | Prevents human contamination |
| Sterilizing tools | Avoids transferring microbes |
| Cleaning workspaces | Removes bacteria/fungi from surfaces |
| Minimal talking/movement | Reduces airborne contamination |
| Flaming inoculation loops | Destroys leftover microbes before/after use |
| Field | Importance |
|---|---|
| Biology labs | Prevents contamination of bacterial cultures |
| Medicine | Avoids infections during surgeries or injections |
| Food | Prevents spoilage, extends shelf life, ensures safety |
| Pharmaceuticals | Ensures medicines are free from pathogens |
Sterile: Completely free from all microorganisms
Aseptic: Free from contamination
Contamination: Introduction of unwanted microbes
Pathogen: Microorganism that causes disease
Pasteurization: Heating to kill harmful microbes (not all)
Written by Kasiban Parthipan