Hi,
I'm checking the cytotoxicity of a plant extract on cancer cells. I prepared my extract in DMSO 100% and make sure it dissolved completely (just by watching it under the light). Then I diluted with PBS that make DMSO's final concentration at 5%. After sterilized filtration, I save it in the freezer (4oC). At the first month, it seems normal but after that, I saw it has precipitate. I used that sample to apply to the cell culture and evaluate the cell viability.
I got the result as the attached image. I don't know why at the second and third treatment (the red boxes), the cell viability is higher than the higher and lower of extract concentration treatment (the first and fourth treatment, respectively).
I repeated this test twice with 3 dependent result for each, but I got the same result. I'm sure that there is no mistake in my manipulation. So I think the problem is relating to the extract.
Unfortunately, I don't have any keyword to find more information now. If you have any idea, please help me.
Thanks.
Hello
After dissolving the plant extract in minimum quantity of DMSO, do not dilute in PBS but use the culture medium to do further dilutions because on storage at low temperature due to high concentration of Na+ in PBS there is a salting out effect seen.
Also make sure that the final concentration of DMSO in the culture medium is 0.1%-0.5% because high concentration of DMSO is toxic to cells. You have used 5% final concentration of DMSO which could turn out to be toxic to cells.
Consider these points before you set up the assay.
Best Wishes.
Dear Trung Nghia I fully agree with Malcolm Nobre
You can read our procedure from the following articles:
https://www.iiste.org/Journals/index.php/JNSR/article/view/51147
https://repository.najah.edu/handle/20.500.11888/8418
Article Screening for antitumor activity of various plant extracts o...
Hi Malcolm Nobre,
Thanks for your comment. I've never heard about the effect of Na+. That's interesting. In addition, 5% of DMSO is a concentration in a ready-to-used sample that I will add to the culture medium (with the cell), so the final DMSO's concentration in the well is around 0.5% or lesser.
To Walid Khalilia,
Thanks for your valuable resources.
- Badges
- Science topic
- Similar topics
- Biological Science
- Botany
- Pharmaceutical Botany
- Plant Extracts