Why do glass petri dishes crack from the bottom when I hit them with the bunsen flame (for further sterilization)?
I'd imagine it's caused by uneven or rapid heating causing stress in the glass. Even pyrex will break if you change its temperature too fast. You could try holding the glass further away from the flame to heat it up more slowly and evenly.
I'd imagine it's caused by uneven or rapid heating causing stress in the glass. Even pyrex will break if you change its temperature too fast. You could try holding the glass further away from the flame to heat it up more slowly and evenly.
I agree with Mr. Bhavin. You must sterilize the plates as he suggests in oven (dry heat) for 2 hour and a half or autoclave (moist heat) for 30 minutes.
Then work near the burner bunsen (cone sterility), but without the glass comes into direct contact with the flame.
Good luck and greetings.
Dear Sony,
Sorry if my words seem to be impolite for you, but hitting glass Petri dishes with flame seems to me to be of no sense at all (besides from burning of unwanted mycelia or sporulation outside the dish) . To obtain sterile dishes it is more effective to use an autoclave or an oven with temperature increasing gradually up to 180C without stressing the glass to cracking. To make a sterile inoculation one should have an upward hot air flow to get rid of contaminants (as it was mentioned by colleagues answered your question previously) and it isn`t presumed the contact of a dish with fire itself. The aim is to get unwanted propagules off and it can be reached with a bunsen burner aside of a dish, but rather close to it.
With best wishes,
Elena
Be thoroughful, calm and slow with heating. Then glass will not crack.
It depends on the quality of the glass the petri dishes are made out off. I reiterate what Prof. Solbach said, they could resist heat better if they are exposed to gentle heating. Good luck.
Agree with Elena,
There is no need of exposing glass petri plates to direct flame. This is a wrong practice. Dry heat sterilization should be the preferred choice of sterilizing glasswares and not direct heat.
Actually As per the current IBC guidelines you can not use bunsen burner in biosafety cabinet. The bondings of HEPA filter may get damaged because of the heat generated inside BSC.
Glass wares tend to crack immediately with sudden heating if they have any moisture content/ residual water during heating. Glass wares should be completely dry. And if heating is done for the purpose of sterilisation then hot air oven or autoclaving is the best , safe and efficient method.
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