Hi,
I was wondering, would it be reliable to compare two cell lines using MTT if I plate them at different densities? For instance, cell line 1 at 1000 cells per well (because it grows faster), and cell line 2 at 3000 (because it grows slower).
I am asking because i feel like the different cell densities might have an impact on how the drug is processed. So the cell line with 3000 will probably show to be more resistant the cell line with 1000.
Regards.
Basically, you can plate them at different densities. You are strongly advised to do a cell number titration first. This issue was discussed some time ago: https://www.researchgate.net/post/For_MTT_assay_how_many_cells_should_we_seed_per_well.
I recommend to try a serial dilution of cells, in order to determine the optimal concentration and the treatment time for each cell line.
You can refer to previous forums for more help.
https://www.researchgate.net/post/Cytotoxicity_assay-cellular_density
https://www.researchgate.net/post/For_MTT_assay_how_many_cells_should_we_seed_per_well.
https://www.ncbi.nlm.nih.gov/books/NBK144065/
Dear Dr. Iwakun,
This is a good question.
As long as the IC50's looks good, I think it is ok to seed at different density's.
You would not want to get growth of the colonies to merge for too high of a seeding density, but not have enough cells to show the effect of the drug(s) being tested.
I get this same problem with the difference of growth rates with GB30 cells (slow) and U251 cells (faster than GB30).
The Inhibitory Concentration 50% is always the main point. Is my Drug range inhibition working at a dose response to that observe vs theory. Can I observe half of the cells growth inhibition at IC50[x] drug contraction.
Mostly being effected by the time and concentration of drug(s) being tested.
Seeding the same number of cells per plate, and adding extra time to make drug dilutions being accurate, and precise to get good IC50's I feel is the most important to understanding the dose response for the MTT assay.
Best Wishes!
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Cell Biology
- Culture Cells
- Cell Line