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The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
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Wed, 17 Feb 2016 11:35:50 +0100
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Dear Aparna,

First off, I'm wondering why you don't simply use a commercially prepared 
BPW. Putting aside the necessary suitability tests that may be necessary 
with your homemade version, I believe your attempt at artisan media 
preparation is already fraught with significant risk. Let me explain : 

- first off, you cite the use of the individual components, but "peptone" 
for example, can be any number of peptones, including soy, casein or meat. 
Each will give a different result when used as a media component. ISO 6579 
for Salmonella testing gives an Enzymatic digest of Casein (typically a 
Tryptone) as example of peptone. On the other hand, the EU Pharmacopeia 
lists peptone as being either casein or meat, when preparing BPW as a 
diluent. Whatever you choose, it must be consistent and the same component 
used every time, lest your results be different. Media, at least those 
prepared for food microbiology, will then need to be validated under NF EN 
ISO 11133 Microbiology of food, animal feed and water - Preparation, 
production, storage and performance testing of culture media .

- Second, it is unwise to prepare media yourself from components (i.e. in 
the misguided notion you will save money or can do it just as well) : the 
reality is you can't, because industrial production has two elements in 
mind : performance and consistency. One way of achieving this is in the 
homogenization of the individual components, something the layman can not 
do on their own. You think its mixed, but true homogenization of 
components require all ingredients to be of the same particle size, in 
order to mix freely. This requires mixing and grinding. Making up media 
from scratch, while necessary in some R & D and independant projects where 
no commercial media exists, will never provide the consistency over time 
that you achieve from commercially prepared formulations. It may work 
once, then work only slightly as well the second time (you use new 
ingredients...) and then not work at all the third time.

- Finally, all media manufacturers, to achieve what I mentioned above, 
namely performance, take the theoretical compostion as a base, and add the 
disclaimer that "composition may be modified to achieve optimal 
performance" or something similar. What this means is that the theoretical 
composition that you are making up is just that : theoretical. And in 
reality, there may be a number of other ingredients not listed that are 
working together to achieve both the consistency and performance that is 
being sought. Some of this can be related to industrial know-how, some can 
be chalked up to achieving consistency because of variability in some of 
the components. Either way, the "recipe" you are following may be either 
close or significantly different to the actual composition in any number 
of commercial formulations, and your homemade version will invariably not 
perform as well.

Sincerely,

David Miller
Sales & Marketing Manager, Biokar Diagnostics
A division of SOLABIA S.A.S.



De :    aparna jagadale <[log in to unmask]>
A :     [log in to unmask]
Date :  16/02/2016 20:17
Objet : [PMFLIST] Media related query
Envoyé par :    The Pharmaceutical Microbiology Forum Email List 
<[log in to unmask]>


Dear Forum Members,

Kindly guide me for the below query:

Earlier i used to prepare "Buffered Peptone" media by weighing each
component      ( peptone,NaCl, Na2HPO4, KH2PO4) as mentioned in USP,add
distilled water & sterilize it. Now, i want to use ready dehydrated
Buffered peptone media, in which i only need to add distilled water &
sterilize it. So what tests i need to carry out to take this media in use?
As per my view, its GPT test will be needed. Do i need to do product
suitability by using this dehyrdated new media?

Kindly help.
Thank you in advance.

Regards.
Aparna Jagadale

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The PMFList (http://microbiologynetwork.com/pmflist.asp) is operated from
The Microbiology Network (http://microbiologynetwork.com) and supported by
our sponsors 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.

Accuratus Lab Services http://www.accuratuslabs.com/

Associates of Cape Cod, Inc. - http://www.acciusa.com/

Nelson Labs - http://www.nelsonlabs.com

BD Diagnostic Systems - http://www.bd.com/ds/

Biolog - http://www.biolog.com

Analytical Research Labs - http://arlok.com/

Charles River-Endosafe and Accugenix - http://www.criver.com/emd

Accugen Laboratories - http://accugenlabs.com

American Type Culture Collection - http://www.atcc.org

ATS Labs - http://www.ats-labs.com

EMD Millipore -  http://www.emdmillipore.com/biomonitoring

Microbiologics, Inc. - http://www.microbiologics.com

Microtest Laboratories, Inc. - http://www.microtestlabs.com

Steris - http://www.sterislifesciences.com/

Veltek Associates, Inc - http://www.sterile.com

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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.

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