Petri Dish Usage Guidelines: Cleaning, Types & Precautions
News 28 3 月, 2025
A Petri dish is an essential laboratory tool for microbial and cell cultures. It consists of a flat, round base and a lid. Due to its fragile nature, handling it with care is crucial. Proper cleaning, sterilization, and storage are key to maintaining its integrity and ensuring accurate experimental results.
How to Clean a Petri Dish?
1. Soaking
- Both new and used glass Petri dishes should be soaked in water to soften residues.
- New dishes: Rinse with tap water, then soak in 5% hydrochloric acid overnight.
- Used dishes: Immediately immerse in water to prevent proteins and oils from drying, making them easier to clean.
2. Scrubbing
- Use a soft-bristled brush and detergent solution to scrub thoroughly, avoiding scratches or damage.
- Ensure all areas are cleaned, with no residue left behind.
3. Acid Bath
- Immerse dishes in an acid solution (cleaning liquid) for at least 6 hours, ideally overnight to remove any remaining contaminants.
- Handle carefully while transferring dishes in and out of the solution.
4. Rinsing
- Proper rinsing is crucial for successful cell cultures.
- After acid treatment, rinse thoroughly by repeating the “fill-drain” method at least 15 times.
- Finally, rinse 2-3 times with distilled water before drying.
5. Sterilization of Disposable Petri Dishes
- Plastic Petri dishes are typically pre-sterilized by gamma irradiation or chemical treatment before shipment.
Types of Petri Dishes
By Usage:
- Cell Culture Petri Dishes
- Bacterial Culture Petri Dishes
By Material:
- Plastic Petri Dishes (single-use or reusable)
- Glass Petri Dishes (for microbial & cell cultures)
By Size:
- Common diameters: 35mm, 60mm, 90mm, 150mm
By Compartments:
- Divided Petri Dishes: 2-section, 3-section dishes for multiple samples
Petri Dish Usage Precautions
Before Use: Always clean and sterilize Petri dishes to prevent contamination. Any residual chemicals may alter pH or inhibit bacterial growth.
New Petri Dishes: Wash with hot water, soak in 1-2% hydrochloric acid for a few hours to remove alkaline substances, then rinse twice with distilled water.
For Bacterial Culture:
- Autoclave sterilization at 121°C, 15 psi for 30 minutes OR
- Dry heat sterilization at 120°C for 2 hours in an oven.
Only sterilized Petri dishes should be used for culturing.