Rapid measurement of total antioxidant capacity in plants

Nat Protoc. 2007;2(4):867-70. doi: 10.1038/nprot.2007.100.


There is growing interest in measuring the antioxidant status of plant tissues. This protocol describes the oxygen radical absorbance capacity (ORAC) assay, which measures antioxidant inhibition of peroxyl radical-induced oxidations and is a measure of total antioxidant capacity. The assay is performed in a microplate and is assessed with a 96-well multi-detection plate reader. Total antioxidant capacity of 64 experimental samples can easily be analyzed in 1 d. This assay is presented along with rapid assays for total phenolic content and total ascorbate content. Overall, these assays provide a general diagnostic tool of the antioxidant capacity in leaf tissue extracts.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antioxidants / analysis*
  • Fluorescent Dyes / analysis
  • Plants / chemistry
  • Plants / metabolism*
  • Reactive Oxygen Species / analysis*
  • Spectrometry, Fluorescence / methods*


  • Antioxidants
  • Fluorescent Dyes
  • Reactive Oxygen Species