How to kill yeast cells :) - chloramine or autoclaving (May/27/2008 )

Hello,

I would like to ask you if it is possible to destroy yeast cells grown on agar plates (or in culture medium) with chloramine (like cell cultures) or you have to autoclave the plates ?! I treat the cells with chloramine and after 2 days they were still alive - maybe (I put a small drop of cells grown in culture medium and check it under the microscope)...

Thanks...

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Definitely autoclave!!!! Any kind of microorganism contamination should be killed by autoclaving as some can make really really resistant dormant bodies (any kind of spores or some encyst them selfs) which can survive for a long time (more than 10 years) very adverse environmental conditions!

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Or incinerate

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another over - kill: CAREFULLY nitate some glycerin, add yeast cells and throw as far away as you can!

Just joking! Please stay save and autoclave the yeasts!

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Thank you very much for an answer:) Now, I really dont know if I should smile or cry Because for a half of the year I used chloramine:))) So it means that my yeast are still alive somewhere:))))
So, please now tell me how can I autoclave my yeast cells. I read somewhere that I have to put the plates into pocket and autoclave it for 5 minutes. Am I right or not? Have you got another tip how to do it?
Desperate yeast scientist )))

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What are you doing with your yeasts? Usually your lab should be equipped with basic microbiology- equippment like laminar flow or autoclave
To kill bacteria or fungi (including yeasts) you should put them in an autoclave for 15- 20 min at 121 °C. A special autoclave bag will be useful, as it (usually) prevents the agar from spilling all over the autoclave....and saves you usually a lot of cleaning but boxes....are fine too.

For an overview on sterilization techniques see: http://en.wikipedia.org/wiki/Sterilization...m_sterilization

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Thanks very very much for a help In our laboratory nobody else is working with yeast besides me (they are working with cell cultures), so for me it is a hard work sometimes:( We are equip with autoclave, but we are using it for autoclaving solutions, tips, and so on... so I am afraid of using it for killing the yeast:((( I dont have mentioned "special autoclave bag". And what about the yeast cells in culture medium? Isnt it another choice of killing the yeast (for e. with some chemicals)?

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If you want to kill all your yeast-cells ultimatively, autoclave them. Fungi are quite resitent (we had them in EtBr Stock, in the acridinorange....very toxic mutagens, but they were gowing happily).

There are "Polypropylene autoclave bags for biohazardous wastes" but sometimes these leak and you will have to clean the autoclave ; otherwise put your plates into some kind of box which can stand the autoclaving process (something made of metal or polypropylen) to prevent the agar from running out (as your plates will melt in the autoclave).
When you have your culture medium in glass ware: Just put into the autoclave. When using plastic-ware: use a box to prevent leaking your medium (as you dont want to clean the autoclave )

And usually everything should be dead after autoclaving, so this should be no problem with the other things sterilised in the autoclave. If you have paranoid people in your lab: kill your yeasts for 30 min 121 °C, make sure that the autoclave is clean but usually nothing will happen. We are autoclaving buffers, tips etc. together with our fungi we want to dispose off....and have no problem with contamination (at least non coming from the autoclave )

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Oh no, so it means that till now my main laboratory work will be autoclaving:))))
But nevertheless, thank you very much for everything....

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Do you have so many cultures and only a small autoclave? If this is the case: Think about smaller petri dishes!

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