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Sodium Hypochlorite to kill bacteria - Alternatives to autoclaving bacterial cultures (Dec/30/2009 )

Hi there,

I know there are varying ideas on what should be done to dispose of bacterial cultures. I've been in a lab where they autoclave and pour down the sink, alt. I've heard of labs using bleach to kill bacteria and then pouring down the sink.

Just trying to get a feel for the % one might use to kill the critters before pouring it down the sink?

Thanks, pretty simple question but hmmm not much out there on the web.



the only thing i know is that most of the FACS machines get desinfected by rinsing them with 1% Sodium Hypochlorit i think this should be enough?!

But i would not recommend it to do it that way ...every lab has an autoclave somewhere. Hypochlorit can be dangerous when it desintegrates ...or there is even the threat of explosions (e.g. reactions with methanol that some people use for the induction of yeast cultures!).

So be careful B)



Are your critters pathogenic? For non-human pathogenic stuff, we just add dish liquid, shake it up, and let it sit for a while. Otherwise we autoclave!


We autoclave empty used tubes and used plates, cool, and dispose of in the normal trash. We add 10% household bleach to liquid cultures, mix, and dispose of down the drain. Contaminated sharps and tips are collected and incinerated (off site).


Hi Thanks for all the info everyone. Generally we do what phage 434 does. As for as I know they are BL-21 (variations), XL-1 Blue, occassionally we use Origami, DH5a. I suspect they are non-human pathogenic but not too sure on that. I'll hit those critters with 10% bleach, that'll probably do the job.



We use 50% bleach solution to kill pathogenic bacteria we work with in the lab (this was determined by a time study we did...50% bleach killed 100% of the spores in 5 minutes). You can probably use a 10% solution, let it sit for 10-30 minutes, and then pour it down the sink. This is a very common practice when you have to decon materials before they can be brought out of the lab or BSC. Happy deconing ;)


Our Environmental Health & Safety people say to kill bacteria with 10% bleach before pouring down the drain. I'd probably up that if you're using spore-formers (as Tiptoes recommends), or incubate the cells (65C) after bringing them to 10% bleach...
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