Stupid mistake when preparing medium - (Nov/12/2007 )
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!!!
Travis
check this thread http://www.protocol-online.org/forums/inde...ium+bicarbonate
yes you can redo the sodium bicarbonate , pH, and filter.
You can but check the Molarity depands on the volume of the medium to be prepare
Regards
siva
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!!!
Travis
Can I ask a stupid question:
Why are you filtering RPMI when the media comes sterile from the company, and all the additives like Pen/Strep?Glutamine?FCS/Non essential amino acids etc etc etc ....COME STERILE ?
Rhombus
I believe he/she was making it from powder.
Yea I am making RPMI from powder, so I need to do all those steps. Thanks guys, now I have to pour back out all the medium and redo the steps again. Well... kinda happy that I can reuse them, at least I won't waste it.
when you add the bicarbonate and adjust the pH you may significantly increase the volume and change the concentration of the components.
what we do in similar situations is add more stock for a higher target volume then adjust pH and bring to final volume.
I am not being funny but we have not made up powdered media for the last 20 years. The bottle filters (0.2uM) are expensive and therefore any cost saving via buying powdered media is lost via the filters ?
Please explain the reasons for still using powdered media.
[If you just change the filter it’s not expensive.
We use ready to use medium, but I know a lab who do it.