Abstract: Method and compositions for determining oxidative stress in a subject are provided in which presence of an aldehyde in a biological fluid is correlated with an oxidative stress in a subject. A test reagent having a pH regulator, a reducing agent, and an aldehyde-reactive chromogen is mixed with the biological fluid, and the color of the resulting aldehyde-modified chromogen is correlated with the oxidative stress.

Abstract: Urine is tested for presence of malondialdehyde by mixing it with a reagent consisting of about 90-110 parts 20% acetic acid, about 13.5-16.5 parts Ingredient A, and about 4.5-5.5 parts Ingredient B, wherein Ingredient A is comprised of sodium metabisulfite, phosphoric acid and deionized water in the proportions of about 18-22 grams sodium metabisulfite, 9-11 ml of concentrated phosphoric acid, and about 450-550 ml deionized water, and Ingredient B is comprised of basic fuchsin and Ingredient A in the proportion of about 0.45-0.55 grams basic fuchsin to about 90-110 ml Ingredient A. A color change is observed when malondialdehyde is present in the urine in a concentration greater than about 2 ppm.