These are definately contaminants. In such plates through moisture these do contaminate master E. coli colonies as well. If you donot need E. coli donot open the plate and discard the plate in scientific practices otherwise streak purify your master cells. Dont waste your time thinking much about the nature of contamination. It can be of diverse type. On 8 May 2014 22:36, <[email protected]> wrote:
> Send Methods mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.bio.net/biomail/listinfo/methods > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Methods digest..." > > > Today's Topics: > > 1. Re: Yellow and Orange Colonies on Kan Plates?! (DK) > 2. RE: Yellow and Orange Colonies on Kan Plates?! > (Hiranya Roychowdhury) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 07 May 2014 14:38:18 GMT > From: [email protected] (DK) > Subject: Re: Yellow and Orange Colonies on Kan Plates?! > To: [email protected] > Message-ID: <[email protected]> > > In article <[email protected]>, WS < > [email protected]> wrote: > >Dear Colleagues, > > > >I have stored some bacterial plates with DH5a and HB2151 on 25ug/ml > Kanamycin > > sealed in the fridge for 3-4 weeks. Now I'm noticing a few big yellow > opaque > > colonies and more "standard sized" colonies which are orange and > translucent. > > Fungi. Unlike most bacteria, they can grow at +4C. Not that unusual > considering > that most E.coli work is done at the bench. > > DK > > > ------------------------------ > > Message: 2 > Date: Wed, 7 May 2014 20:54:34 +0000 > From: Hiranya Roychowdhury <[email protected]> > Subject: RE: Yellow and Orange Colonies on Kan Plates?! > To: WS <[email protected]>, > "[email protected]" < > [email protected]> > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > These could be S. aureus and/or Micrococci (orange-red). They do grow at 4C > > Hiranya S. Roychowdhury, Ph.D. > Associate Professor > Health & Public Services > NMSU-Dona Ana Community College > 575 527 7725 (office) > > Co-Chair, Curriculum & Instruction Committee > Human Anatomy and Physiology Society > > > ________________________________________ > From: [email protected] < > [email protected]> on behalf of WS < > [email protected]> > Sent: Tuesday, May 6, 2014 4:48 AM > To: [email protected] > Subject: Yellow and Orange Colonies on Kan Plates?! > > Dear Colleagues, > > I have stored some bacterial plates with DH5a and HB2151 on 25ug/ml > Kanamycin sealed in the fridge for 3-4 weeks. Now I'm noticing a few big > yellow opaque colonies and more "standard sized" colonies which are orange > and translucent. > > Any ideas what contaminants I might have acquired? Is it safe to open the > dishes or should I better autoclave them as they are? > > Thanks for your comments > > WS > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > > > > ------------------------------ > > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > > End of Methods Digest, Vol 107, Issue 2 > *************************************** > _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
