Thanks.
We always verify with a plate count. This is just to get in the
ballpark. Right now the analyst just uses experience to estimate the
turbidity of the suspension, but we thought we might want to have a more
scientific method, since sometimes experience doesn't work very well.
Regards,
Jayne
Jayne Henry
Microbiology Laboratory Manager
Perritt Laboratories, Inc.
145 South Main St.
PO Box 147
Hightstown, NJ 08520
Phone: 609-443-4848
Fax: 609-443-5293
-----Original Message-----
From: The Pharmaceutical Microbiology Forum Email List
[mailto:[log in to unmask]] On Behalf Of Ambrus, Kate
Sent: Monday, May 15, 2006 11:43 AM
To: [log in to unmask]
Subject: Re: [PMFLIST] Optical Density Ranges for Preparing Organism
Inoculum for the AET Test
Hello Jayne,
The answer will depend on the wavelength and the instrument you are
using. I can give you the approximate absorbancies we use at 600 nm as a
starting reference, but you will need to validate them with your plate
count.
Our instrument is Spectronic 21 or 20+, and at 600 nm, we use the
approximate ranges below. Of course every day we read the absorbancy,
and then perform a plate count. The plate count is the final value - the
absobancy is just a preliminary estimate.
Staph. aureus ~0.15
Ps. aeruginosa ~0.1
E. coli ~0.1
C. albicans (1:10 dilution) ~0.5
This is for cultures grown per USP or FDA/ISO specifically for the
antimicrobial preservative efficacy test.
Kate S. Ambrus
Manager, Eye Care R&D Microbiology
Advanced Medical Optics
[log in to unmask]
(714) 247-8318
-----Original Message-----
From: The Pharmaceutical Microbiology Forum Email List
[mailto:[log in to unmask]] On Behalf Of Machtiger, Neal
Sent: Friday, May 12, 2006 1:23 PM
To: [log in to unmask]
Subject: Re: [PMFLIST] Optical Density Ranges for Preparing Organism
Inocu lum for the AET Test
I have always run my own calibration curves vs. colony counts.
Variables include wave length, instrument, medium, growth conditions
(for example shaken {shaker speed]) vs. static, etc., etc.
Neal
Neal A. Machtiger, Ph.D.
Technical Manager
Industrial Biocides and Personal Care Preservatives
Office: 973-628-3902
Home Office: 732-257-6115
Home Fax: 732-257-4668
Mobile: 732-309-2831
-----Original Message-----
From: The Pharmaceutical Microbiology Forum Email List
[mailto:[log in to unmask]] On Behalf Of Jayne Henry
Sent: Thursday, May 11, 2006 4:24 PM
To: [log in to unmask]
Subject: [PMFLIST] Optical Density Ranges for Preparing Organism
Inoculum for the AET Test
Hi All,
Does anybody know (or have a reference for) the optical density ranges
used to prepare standard organism suspensions (between 1.0 x 10e5 to 1.0
x
10e6)
for the AET Test? We need the ranges for S. aureus, E. coli, P.
aeruginosa and C. albicans. I used to know them in at a former company,
but no longer have access to that information.
Thanks,
Jayne
Jayne Henry
Microbiology Laboratory Manager
Perritt Laboratories, Inc.
145 South Main St.
PO Box 147
Hightstown, NJ 08520
Phone: 609-443-4848
Fax: 609-443-5293
------------------
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.
Please take a second to visit our sponsors' web sites and say thank you
for their support of this service.
Accugenix - http://www.accugenix.com
American Type Culture Collection - http://www.atcc.org
ATS Laboratories - http://www.ats-labs.com
Biolog - http://www.biolog.com
Biomerieux - http://industry.biomerieux-usa.com
Dupont Qualicon - http://www.qualicon.com
EMD Chemicals - http://www.emdchemicals.com
EMSL Analytical, Inc. - http://www.emsl.com
Genomic Profiling Systems, Inc. - http://www.genprosys.com
MIDI, Inc. - http://www.midi-inc.com
Millipore - http://www.millipore.com
Pall - http://www.pall.com
NovaTek International - http://www.ntint.com
Raven Biological Labs - http://www.ravenlabs.com
Veltek Associates, Inc - http://www.sterile.com
=================================
The nature of this service is to provide a medium for communication.
The
specific statements and endorsements of individuals participating in the
discussions are not necessarily those of The Microbiology Network, Inc.,
the PMF, or the sponsors of the list.
------------------
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.
Please take a second to visit our sponsors' web sites and say thank you
for their support of this service.
Accugenix - http://www.accugenix.com
American Type Culture Collection - http://www.atcc.org
ATS Laboratories - http://www.ats-labs.com
Biolog - http://www.biolog.com
Biomerieux - http://industry.biomerieux-usa.com
Dupont Qualicon - http://www.qualicon.com
EMD Chemicals - http://www.emdchemicals.com
EMSL Analytical, Inc. - http://www.emsl.com
Genomic Profiling Systems, Inc. - http://www.genprosys.com
MIDI, Inc. - http://www.midi-inc.com
Millipore - http://www.millipore.com
Pall - http://www.pall.com
NovaTek International - http://www.ntint.com
Raven Biological Labs - http://www.ravenlabs.com
Veltek Associates, Inc - http://www.sterile.com
=================================
The nature of this service is to provide a medium for communication.
The specific statements and endorsements of individuals participating in
the discussions are not necessarily those of The Microbiology Network,
Inc., the PMF, or the sponsors of the list.
------------------
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.
Please take a second to visit our sponsors' web sites and say thank you
for their support of this service.
Accugenix - http://www.accugenix.com
American Type Culture Collection - http://www.atcc.org
ATS Laboratories - http://www.ats-labs.com
Biolog - http://www.biolog.com
Biomerieux - http://industry.biomerieux-usa.com
Dupont Qualicon - http://www.qualicon.com
EMD Chemicals - http://www.emdchemicals.com
EMSL Analytical, Inc. - http://www.emsl.com
Genomic Profiling Systems, Inc. - http://www.genprosys.com
MIDI, Inc. - http://www.midi-inc.com
Millipore - http://www.millipore.com
Pall - http://www.pall.com
NovaTek International - http://www.ntint.com
Raven Biological Labs - http://www.ravenlabs.com
Veltek Associates, Inc - http://www.sterile.com
=================================
The nature of this service is to provide a medium for communication.
The specific statements and endorsements of individuals participating in
the discussions are not necessarily those of The Microbiology Network,
Inc., the PMF, or the sponsors of the list.
------------------
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.
Please take a second to visit our sponsors' web sites and say thank you for their support of this service.
Accugenix - http://www.accugenix.com
American Type Culture Collection - http://www.atcc.org
ATS Laboratories - http://www.ats-labs.com
Biolog - http://www.biolog.com
Biomerieux - http://industry.biomerieux-usa.com
Dupont Qualicon - http://www.qualicon.com
EMD Chemicals - http://www.emdchemicals.com
EMSL Analytical, Inc. - http://www.emsl.com
Genomic Profiling Systems, Inc. - http://www.genprosys.com
MIDI, Inc. - http://www.midi-inc.com
Millipore - http://www.millipore.com
Pall - http://www.pall.com
NovaTek International - http://www.ntint.com
Raven Biological Labs - http://www.ravenlabs.com
Veltek Associates, Inc - http://www.sterile.com
=================================
The nature of this service is to provide a medium for communication. The specific statements and endorsements of individuals participating in the discussions are not necessarily those of The Microbiology Network, Inc., the PMF, or the sponsors of the list.