I performed an MTT assay to see the effect of an inhibitor on AGS cells. I seeded them on Day 1, added the inhibitor on Day 2 and performed the MTT assay on Day 3 (left the inhibitor act for 24 HRS). I got a little weaker signal on the treated cells, compared to the control. How do I know if the inhibitor caused cytotoxicity or if it inhibited cell proliferation?
Hi Osmar,
A possibility is determine cell viability by means of the trypan blue exclusion test, in order to compare the number of viable cells after treatment comparing with the number of viable cells in the untreated cells.
MTT, XTT, SRB are assays for cell cytotoxicity. For cell viability you can go for trypan blue or Calcein-AM which will tell you about rate of proliferation as well as the percentage of viable cells. You can use specific cell proliferation markers such as proliferating cell nuclear antigen PCNA, topoisomerase IIB etc. And the most accurate I believe you should study DNA synthesis (bromodeoxyuridine (BrdU) method).
Dear Osmar, you must count meticulously the number of cells seeded at day zero and recount them after treatment at day 2, 3, etc by any available method. So you can take a broader view on the effect of your drug. Furthermore, you can estimate LD50 and GI50 by using different drug concentrations.
- Badges
- Science topic
- Similar topics
- Chemistry
- Pharmacology
- Pharmaceuticals
- Drugs