MTT stock solution (5 mg/ mL) color is normal.
But when MTT solution adds in medium (MEN/DMEM with 10% FBS) (without cell),
the solution soon changes color to dark purple.
Why dose my MTT solution changes color to Purple before adding ?
Hi
Perhaps try testing a new bottle of MEM? With and without FBS. If MEM+FBS has worked well previously as you say then I would guess that there is some kind of contamination in your media.
Best of Luck,
MTT can react with serum components, I would recommend using serum-free medium or even PBS for MTT assay.
Have you tried on PBS? maybe It's the stock solution. I use it in RPMI 10% FBS and I dont have any problem
To Andrea Maria Guarino : have phenol red.
To Ana González-Corpasl: I have tried in PBS. But it seems that is needed more reaction time. (more than 4 hr)
To Olga Shilova: I'll try in serum-free medium.
Today, I used DMEM (+FBS) to test and the solution color is normal.
But MEM (+FBS) still change color.
I'm so confused, because the previous test didn't have any problem.
Thank you everyone~
Hi
Perhaps try testing a new bottle of MEM? With and without FBS. If MEM+FBS has worked well previously as you say then I would guess that there is some kind of contamination in your media.
Best of Luck,
Hi Wei Lin Chen,
When you said "[stock solution] color is normal", do you mean yellow?
If your solution DMEM+FBS is fine with the MTT, and if your control cells well respond to this media, maybe you could think to use it..
Hi
I would recommend that you try with DMEM/High Modified (1x) without phenol red and serum-free medium.I used to use PBS.At 4 hrs,the cell become dead.
I would agree with Alan Hibbits about trying new bottle of medium, as bacterial contamination leads to fast and noticable color change with no regard to investigated eucaryotic cells.
Hi,
I completely agree with Olga, we had earlier observed an extremely high MTT metabolism rate in single wells accidently (and visibly) contaminated with bacteria when directly compared to those with only cells.
We routinely use phenol-red-free DMEM for the MTT assay, but have been using media with phenol red earlier without any significant chemical interaction with the medium.
As others mentioned, your media can be contaminated. It is always better to use MTT in Media with no phenol red.
I used the new MEM medium (ready to use) to try, it doesn’t change color before adding.
As others mentioned, maybe medium powder is contaminated.
Thank you so much.
- Badges
- Science topic