Option #2 is always the intent in this context.  The goal is the FINAL 
concentration of whatever % you want.

C

Carl A. Boswell, Ph.D.
Molecular and Cellular Biology
University of Arizona
520-954-7053
FAX 520-621-3709
----- Original Message ----- 
From: "B. Prabhakar Pandian" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, October 22, 2009 1:54 PM
Subject: Re: Cell Media Preparation Debate


> Hello Mike,
>                       I know that from the mathematical stand point what 
> you are saying is correct, but the contention is more from what 10% 
> actually means. Is it to add 10% of the original volume of
> serum (option # 1) to the media or to make sure that the final 
> concentration is 10% (option # 2).
>
> Thanks,
>
> Mike Tighe wrote:
>> If total volume is 550mls (500ml media and 50mls serum you will have 
>> 9.1%  serum. Not 10% but probably enough to keep most cells happy
>>
>> Mike
>>
>>>>> "B. Prabhakar Pandian" <[log in to unmask]> 10/22/09 3:10 PM >>>
>> Hello,
>>              In our laboratory there has been recent debates on the cell 
>> media preparation. The point of contention is the presence of serum in 
>> media.
>> When a media mentions supplemented with 10% serum, which of the following 
>> is correct for a 500ml media bottle.
>>
>> 1. Add 50ml of serum to the media bottle (total volume is 550ml)
>>
>> 2. Remove 50ml of media and then add 50ml of serum (total volume is 
>> 500ml).
>>
>> Any information on the right usage will be great.
>>
>> Thanks,
>>
>> - Bala
>>
>>
>>
>
>
> -- 
>