BAP Test

The BAP Test (Biological Antioxidant Potential Test) is a photometric test that can determine in the blood the concentration of antioxidant substances capable of reducing iron from ferric to ferrous status. 

The BAP Test allows a global evaluation of many antioxidants, as uric acid, ascorbic acid, proteins, a-tocopherol, bilirubin and others.


In the blood, the defense against noxious attack of reactive species and particularly, against free radicals, is guaranteed by so-called plasma antioxidant barrier.

The anti-oxidant power of the anti-oxidant barrier can be measured not only by assessing the capability of the plasma to oppose to a predetermined oxidising agent (the hypoclorous acid, in the OXY-Adsorbent Test), but also by assessing a determined oxidising substrate chosen on its redox potential basis.

In the BAP (Biological Antioxicand Potential) the antioxidant power, thus reducing power, of the plasma is evaluated measuring the capacity of the sample to reduce the iron (placed in a solution of ferric cloride) from ferric (Fe3+) to ferrous (Fe2+).

With BAP Test therefore we measure the fraction of the anti-oxidant barrier directly active in a chemical point of view, encompassing both exogenous antioxidants (such as vitamin C, vitamin E, carotenoids, Bioflavonoids, ...) and endogenous antioxidants (like bilirubin, uric acid, cholesterol, protein, etc.). Some of these substances exhibit a scavenger-type activities, i.e. neutralize free radicals interacting directly with them.

Reference Values

The normal value is higher than 2200 μmol/L of antioxidant substances such as Vitamin C. A reduction of the value under this interval suggest a direct correlation with a reduced activity of the plasmatic antioxidant barrier.

Reference values as μmol/L of Vit.C
used as a iron-reducing agent reference
< 2200 Optimum value
2200 - 2000 Border-line condition
2000 - 1800 Slight deficiency status
1800 - 1600 Deficiency status
1600 - 1400 High deficiency status
< 1400 Very high deficiency status

This test is particularly useful when a precise evaluation of the specific and/or antioxidant treatment efficacy is required (i. e. during oxidative stress-related diseases).

The BAP Test, through an accurate measurement of antioxidant status, provides the clinician an information on the general well-being of the organism which also depends on the physiological efficiency of antioxidant defense systems.
It should be noted that the BAP Test represents a complementary test to the d-ROMs Test: their simultaneous determination provides an accurate picture of the oxidative balance status, the starting point for any eventual treatment.
In this regard, it should be noted that the BAP Test proves an invaluable tool to monitor the efficacy of antioxidant treatments, being extremely sensitive to the supply of antioxidants in the diet.

Experimental confirmation

A study of the University of Tokyo, Japan, has shown, through electron resonance spectroscopy (EPR/ESR), that bilirubin - a natural product of catabolism of hemoglobin normally present in plasma – possesses “in vitro” a direct scavenger activity against hydroxyl radical (the most fearsome tissue-damaging radical) and 1.1-diphenyl-2-picrilidrazile also at physiological concentrations. Experiments conducted in parallel with the BAP Test have shown that the results obtained by the two methods were similar.

As the EPR/ESR is the "golden standard" for the study of free radicals, the BAP Test is considered, thanks to this authoritative validation, a test able to detect and quantify specifically and reliably the scavenging/antioxidating activity, confirming the principle it is based on.

Working Conditions

BAP Test can be carried out either on fresh heparinized plasma or serum. It can be carried both on dedicated systems (FREE Carpe Diem and FREE DUO) and on standard photometer or automatic analyzers. Working conditions experimentally determined and standardized for the BAP Test are as follows: wavelength 505, 1 cm optical path, and 37° C temperature. Based on the data published so far, the BAP Test is a reliable, accurate, repeatable test, with inter and intra-CV series totally acceptable, even with manual procedure.

Clinical studies

The BAP Test has proved to be very useful in many clinical studies in both human and veterinary field for the assessment of antioxidant potential, always in combination with the d-ROMs Test.

For example, in patients with neurologic trauma it proved to be a reliable method to demonstrate the antioxidant activities of bilirubin even at physiological concentrations, with results that are perfectly similar to those obtained using electron resonance spectroscopy (EPR/ESR). In addition, the clinical utility of the BAP Test was documented in underwater and hyperbaric medicine, in patients with chronic and degenerative diseases, athletes and even in subjects who underwent acupuncture.

Similar promising results were obtained in veterinary medicine, for example on Labradors, where the BAP test proved to be useful to monitor the effectiveness of specific antioxidant supplements.


DIACRON INTERNATIONAL s.r.l is the leader company in research and evaluation of oxidative stress. Our company produces and sells analytical dedicated instruments, kits and accessories for oxidative stress assessment in Human, Veterinary and Agrifood fields.