Jump to content

  • Log in with Facebook Log in with Twitter Log in with Windows Live Log In with Google      Sign In   
  • Create Account

Submit your paper to J Biol Methods today!
Photo

Longevity of plain LB agar plates


  • Please log in to reply
10 replies to this topic

#1 seanspotatobusiness

seanspotatobusiness

    Veteran

  • Active Members
  • PipPipPipPipPipPipPipPipPipPip
  • 175 posts
7
Neutral

Posted 02 September 2009 - 03:44 AM

How long to plain (no antibiotic) LB plates last?

My plan is to make use of other people's old (>1 month) and unwanted ampicilin plates but just spreading fresh antibiotic on top.

#2 phage434

phage434

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 2,509 posts
254
Excellent

Posted 02 September 2009 - 04:56 AM

If they have been in the refrigerator, you probably need not do anything -- they will be fine as is. LB plates which are not dried out and have no growth are good nearly indefinitely, in my experience. The antibiotic may degrade over time, and X-Gal definitely does. Tet plates are light sensitive.

#3 pito

pito

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 1,338 posts
82
Excellent

Posted 02 September 2009 - 06:09 AM

I agree with phage434.

But about the antibiotic: we never use them if its older then 4weeks.


Thus you will need to put some new antibiotic on the plates.

If you don't know it, then ask it! Better to ask and look foolish to some than not ask and stay stupid.


#4 pito

pito

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 1,338 posts
82
Excellent

Posted 02 September 2009 - 06:10 AM

I agree with phage434.

But about the antibiotic: we never use them if its older then 4weeks.


Thus you will need to put some new antibiotic on the plates.
(I have never done that before, not sure if thats ok to do. If I would do that: I would pore the antibiotic on it, spread it and then let it dry.... and also: its not easy to get the propper concentration of antibiotic then...)

If you don't know it, then ask it! Better to ask and look foolish to some than not ask and stay stupid.


#5 GeorgeWolff

GeorgeWolff

    Veteran

  • Active Members
  • PipPipPipPipPipPipPipPipPipPip
  • 294 posts
1
Neutral

Posted 04 September 2009 - 02:15 AM

That is real sloppy science. You have no idea the quality of the media (other peoples old plate they don't want) and wil certainly end up with sme high but undetermined level of ampicillin.

Start over.

#6 hanming86

hanming86

    Veteran

  • Active Members
  • PipPipPipPipPipPipPipPipPipPip
  • 156 posts
2
Neutral

Posted 04 September 2009 - 06:12 AM

Why would u even wanna do that in the first place? u guys run out of LB or something?

I personally don't really like to use other ppl's stuff whenever possible.
Lab + Coffee + Music = Bliss

#7 pito

pito

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 1,338 posts
82
Excellent

Posted 05 September 2009 - 09:40 AM

Why would u even wanna do that in the first place? u guys run out of LB or something?

I personally don't really like to use other ppl's stuff whenever possible.



In general I agree with what you and GeorgeWolff, but if we are talking about plain agar plates, there is nothing wrong with using "older" plates.
If the plates are there and no one uses them... then why let them go to waste.

If you need plates with an antibiotic in it, then we speak of different things.

If you don't know it, then ask it! Better to ask and look foolish to some than not ask and stay stupid.


#8 hanming86

hanming86

    Veteran

  • Active Members
  • PipPipPipPipPipPipPipPipPipPip
  • 156 posts
2
Neutral

Posted 05 September 2009 - 06:38 PM

Replying pito,

because, you will never know what's actually inside the LB plate unless u make it yourself.

It could have been labelled LB but actually contained something else that only the one making em knows.

So to be on the safe side , i still prefer whenever possible to make my own stuff.

there's nothing wrong with using you OWN old plates however. i can live with that.
Lab + Coffee + Music = Bliss

#9 pito

pito

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 1,338 posts
82
Excellent

Posted 06 September 2009 - 08:58 AM

Replying pito,

because, you will never know what's actually inside the LB plate unless u make it yourself.

It could have been labelled LB but actually contained something else that only the one making em knows.

So to be on the safe side , i still prefer whenever possible to make my own stuff.

there's nothing wrong with using you OWN old plates however. i can live with that.



Yeah, that is true.

You are indeed correct, however I am assuming that he asks what kind of plates it are...
I just depends on the circumstances..
But indeed, you are right, as GeorgeWolff is too.

If you don't know it, then ask it! Better to ask and look foolish to some than not ask and stay stupid.


#10 eberthella

eberthella

    Enthusiast

  • Active Members
  • PipPipPipPipPip
  • 53 posts
0
Neutral

Posted 09 September 2009 - 02:50 AM

I vote with you and georgie, pito. What surprises me is the "sloppy science" (per georgie) the question suggests. Most folks are pretty jealous of their scientific rigor and this one found some old antibiotic plates in the frig and wants to toss on some more antibiotic and use 'em.

#11 swanny

swanny

    Veteran

  • Active Members
  • PipPipPipPipPipPipPipPipPipPip
  • 367 posts
8
Neutral

Posted 09 September 2009 - 11:13 PM

By the time this debate reaches its conclusion (or else dies a slow painful death of inactivity) the plates will be either so old (probably desiccated to the consistency of the plastic dish they are in) that nothing will grow on them, or contaminated so you'd not want to use them.
Heart disease kills more women than breast cancer, but heart attack symptoms differ from men's symptoms. Get to know your heart... it could save your life.




Home - About - Terms of Service - Privacy - Contact Us

©1999-2013 Protocol Online, All rights reserved.