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Stupid mistake when preparing medium - (Nov/12/2007 )

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I quite like it here in the dark ages Rhombus, we can't all be as perfect as you smile.gif


QUOTE (dave2 @ Nov 15 2007, 07:50 AM)
QUOTE (Travis @ Nov 12 2007, 08:42 PM)
Hi everyone,

Last week I was filtering RPMI 1640 medium for I am almost out of medium. When I was stirring the medium and calculating the pH, I forgot to add in sodium bicarbonate before measuring pH. Now I have all my medium filtered and in bottle. But the color of the medium is not as red as it should be, and that's how I realize my mistake. May I ask whats the role of sodium bicarbonate in RPMI? also, can I pour all the medium out and redo the sodium bicarbonate, pH measure, and filter steps to fix this situation? Thanks alot!!!


RPMI has different formulas that seem to always be changing based on what is needed. Some of the powders are the only ones without certain products. I personally hate using media with phenol red in it when I am culturing mnc because I like to see the cells without the color present.
Bicarbonate is used to buffer the carbonic acid (H2C03) that forms when C02 is present in the media during culturing. The amount of (C02) is proportional to the amount of bicarbonate (HC03) used.

Thanks alot for helping me out, it really helps alot thanks!


Thanks for all of you who helped. This really helps me in solving my problem. The information you guys provided are very useful and I have never expected you guys will give me so many advice. Thanks, you guys rock!!!

And why my lab is still using powder form RPMI and filter it ourselve. Well, I am just an undergrad, so I am not sure. But I think it's cheaper. It is because everytime we filter the medium we will just change the new filter. The bottle for filtering will be washed, autoclaved, and use again.


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