Oxidative stress ecology and the d-ROMs test: facts, misfacts and an appraisal of a decade's work

In recent years, behavioural ecologists have taken to studying oxidative stress in free-ranging organisms because it has been proposed as an important mediator of life-history trade-offs. A plethora of methodological approaches to quantify biomarkers associated with oxidative stress exist, each one with its own strengths and weaknesses. The d-ROMs test has emerged as one of the favoured assays in ecological studies because of its reliability, sensitivity to specific perturbations of the organism's oxidative balance and medical and ecological relevance. Criticisms have been, however, raised about its specificity for oxidative damage. In this article, I have reviewed basic information about the d-ROMs test, its validation, the methodological mistakes made in the studies that attempted to criticise this assay and the application of this assay to ecological studies of oxidative stress. All the direct and indirect evidences show that the d-ROMs test is a valuable assay for the quantification of plasma or serum primary (or early) oxidative damage molecules and, possibly, of other biological matrices and provides ecologically relevant information.