ORAC Antioxidant Assay Kit

Free radicals and reactive oxygen species (ROS) are highly reactive molecules that are generated by normal cellular processes, environmental stresses, and UV irradiation. ROS react with cellular components, damaging DNA, carbohydrates, proteins, and lipids causing cellular and tissue injury. Excess production of reactive oxygen species can also lead to inflammation, premature aging disorders, and several disease states, including cancer, diabetes, and atherosclerosis. Organisms have developed complex antioxidant systems to protect themselves from oxidative stress, however, excess ROS can overwhelm the systems and cause severe damage.

The ZenBio ORAC (Oxygen Radical Absorbance Capacity) Antioxidant Assay Kit can be used to determine the total antioxidant capacity of biological fluids, cells, and tissue. It can also be used to assay the antioxidant activity of naturally occurring or synthetic compounds for use as dietary supplements, topical protection, and therapeutics. The assay measures the loss of fluorescein fluorescence over time due to peroxyl-radical formation by the breakdown of AAPH (2,2'-azobis-2-methyl-propanimidamide, dihydrochloride). Trolox [6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid], a water soluble vitamin E analog, serves as a positive control inhibiting fluorescein decay in a dose dependent manner. The ORAC assay is a kinetic assay measuring fluroescein decay and antioxidant protection over time. The antioxidant activity in biological fluids, cells, tissues, and natural extracts can be normalized to equivalent Trolox units to quantify the composite antioxidant activity present. This assay measures antioxidant activity by hydrogen atom transfer and when combined with ZenBio's ABTS antioxidant assay kit, provides a comprehensive analysis of a test sample's antioxidant activity.

ORAC Figure

Ordering Information

Item#Item DescU/MPrice
AOX-2ORAC Antioxidant Assay KitKit$214.00
AOX-2RBORAC Antioxidant Assay Kit, BULK (5 plates)Kit$674.00
TROLOX-STDTrolox Standard, 1.5mM, 20ulEACH$36.00

To see ORAC Antioxidant Assay Kit Manual

Zen Kits – References


  1. Oxygen Radical Absorbance Capacity (ORAC) assay used to measure oxidative stress in exercising human adults (Bloomer, Canale, Blankenship, & Fisher-Wellman, 2010).

ORAC Antioxidant Assay Kit Publications

The mycosporine-like amino acids porphyra-334 and shinorine are antioxidants and direct antagonists of Keap1-Nrf2 binding

Ranko Gacesa, Karl P.Lawrence, Nikolaos D.Georgakopoulos, Kazuo Yabe, Walter C. Dunlap, David J.Barlow, Geoffrey Wells, Antony R.Young, Paul F.Long

Phenolics, antioxidants and color properties of aqueous pigmented plant extracts: Ardisia colorata var. elliptica, Clitoria ternatea, Garcinia mangostana and Syzygium cumini

A.M. Siti Azima , A. Noriham, N. Manshoor

Journal of Functional Foods

Angela R. Hillman, Bryna C.R. Taylor (nee Chrismas), Diahnn Thompkins
Journal of Functional Foods 29 (2017) 185–192