PMFLIST Archives

October 1999

PMFLIST@LISTS.MICROBIOLOGYNETWORK.COM

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Lynch, Karen" <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Mail List <[log in to unmask]>
Date:
Wed, 20 Oct 1999 16:12:11 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (104 lines)
Katherine,

Yes, this is for Total Aerobic Microbial Count, and you're right that it
would be a big job to subculture every colony if for example there were 40
colonies detected.  Although we also perform additional tests to test for
the absence of the USP indicator organisms, colonies detected in TAMC should
be identified to some extent to ensure that they are not objectionable
microorganisms other than the USP indicators.


Karen Lynch
Parke-Davis Research


-----Original Message-----
From: Shih, Katherine [mailto:[log in to unmask]]
Sent: Friday, October 15, 1999 4:36 PM
To: [log in to unmask]
Subject: Re: [PMFLIST] Inhibitory effect of TTC.


Karen:

Is this for the Total Aerobic Microbial Count?  If you have recovered, say,
40 colonies, this would be a big job to subculture every colony as we can
not group them by colony morphology.  For TAMC, do we need to check every
colony that we have recovered if we also have other tests side-by side for
the absence of certain objectionable organisms?  Thanks.

Katherine Shih
Oread

-----Original Message-----
From: Lynch, Karen [mailto:[log in to unmask]]
Sent: Friday, October 15, 1999 9:02 AM
To: [log in to unmask]
Subject: Re: [PMFLIST] Inhibitory effect of TTC.


Laura,

We use 0.5% TTC in our lab to help us differentiate colonies from particles.
We run our test with media that does not contain the TTC and at the end of
the incubation period, we flood the plate with the TTC and allow it to stand
for about one hour to allow it to soak into the media and reach the
subsurface colonies.  We then subculture the colonies immediately and have
not yet had any problems with recovery.  This method has worked quite nicely
for us.  We have no experience with adding the TTC to the media prior to
pouring the individual plates, so I cannot comment on the inhibitory effects
of the TTC when used in that manner.

Karen Lynch
Parke-Davis Research



 -----Original Message-----
From: Laura Acevedo [mailto:[log in to unmask]]
Sent: Thursday, October 14, 1999 6:33 PM
To: [log in to unmask]
Subject: [PMFLIST] Inhibitory effect of TTC.



Dear colleagues,

I perform microbial limit tests using poured plates . With some products
(lactose, starch) it is difficult to distinguish the colonies. I know
there`s the recomedation of using MPN in this cases, but I wonder if it is
possible to use poured plates adding  TTC to the culture medium to stain the
colonies and differentiate them from the product being tested. Has anybody
validated this method? I`ve heard about possible inhibitory effect of TTC.
Could someone refer me any paper on this topic?
Any help would be appreciated, thanks in advance,

Laura Acevedo
Microbiological Quality Control Manager
Laboratorio LIBRA
Montevideo-Uruguay
[log in to unmask] <mailto:[log in to unmask]>


------------------
The PMFList (http://microbiol.org/PMFList_info.htm) is operated from
The Microbiology Network (http://microbiol.org) and supported by
our sponsors (http://microbiol.org/sponsor.htm) as a service to
the scientific community.


------------------
The PMFList (http://microbiol.org/PMFList_info.htm) is operated from
The Microbiology Network (http://microbiol.org) and supported by
our sponsors (http://microbiol.org/sponsor.htm) as a service to
the scientific community.


------------------
The PMFList (http://microbiol.org/PMFList_info.htm) is operated from
The Microbiology Network (http://microbiol.org) and supported by
our sponsors (http://microbiol.org/sponsor.htm) as a service to
the scientific community.



ATOM RSS1 RSS2