Patent ID: 7632633

Claim:
A method of determining the degree of protein oxidation in a skin sample comprising stratum corneum, the method comprising: (a) providing a skin sample (S) selected from the group comprising: (i) stratum corneum having carbonylated protein; or (ii) oxidized stratum corneum, wherein the oxidized stratum corneum is obtained by contacting a skin sample comprising stratum corneum with an oxidizing agent and wherein the oxidizing agent comprises acrolein, thereby forming an acrolein-protein adduct; wherein the skin sample (S) comprising said stratum corneum (i) or said oxidized stratum corneum (ii) is contacted and fluorescently labeled with a hydrazine fluorophore, the hydrazine fluorophore selected from the group consisting of fluorescein-thiosemicarbazide; Texas Red hydrazide; biotin hydrazide reacted with fluorescein avidin; dintrophenylhydrazine (DNPH) reacted with anti-DNP antibody and with a fluorescein-labeled secondary antibody specific to the anti-DNP antibody; and DNPH reacted with a fluorescent dye; (b) measuring the fluorescence of the skin sample (S); and then (c) determining the degree of protein oxidation of the skin sample (S), (i) wherein the fluorescence intensity of the skin sample (S) is indicative of the degree of protein oxidation in the skin sample (S); (ii) wherein, relative to the fluorescence intensity of a skin sample not treated with acrolein (S′), an increased fluorescence intensity of the skin sample (S) indicates an increased protein oxidation in the skin sample (S); and (iii) wherein said skin sample (S) has increased protein oxidation.