I am exploring antioxidant activity of a liquid sample using 0.1mM DPPH (3.94 mg in 100 ml) in ethanol. prepared different concentration (5, 10, 25, 50, 100 microgram per ml) of test and ascorbic acid in ethanol. Absorbency at 517 nm taken. Absorbenc of control (dpph and ethanol) show 0.18. Absorbency of standard ascorbic acid shows 0.115, 0.1, 0.1. etc and for test 0.2402, 0.2, etc. The absorbency of test is more as compare to control. What does it means. Is test sample is more antioxidant or less.
Dissolve dpph in 96 % methanol. adjust the OD around 0.80. if you add sample it should be less than 0.8. if it is coming more means concentration of antioxidants is not sufficient in sample. then increase the concentration of your sample 1000 microg/ml. for details see my paper of zizyphus
Hi Ashu,
Looking at your data it appears that sample itself is having some constituents which increase the OD of the sample. This is rather common for plant extracts. In this case, I would suggest to run a DPPH blank (Only sample+ ethanol) for each sample concentration. You can further subtract this value from the OD you are getting for DPPH+Sample. This will give you the exact value due to scavenging of DPPH radical. Else as Nidhi has suggested, check the activity at lower concentrations.
Hope this helps!
- Badges
- Science topic
- Similar topics
- Biological Science
- Biota
- Eukaryota
- Fungi