Abstract: A method for extracting a low-molecular-weight substance existing in a biological sample, including: 1) an adsorption step of adsorbing the substance on porous carbon by mixing the biological sample with the porous carbon having mesopores of 3.5 nm to 150 nm and micropores of a larger size as a hierarchical structure, and recovering the porous carbon from the obtained mixture, or by bringing the biological sample into contact with a filtration filter on which the porous carbon is disposed or supported; and 2) a releasing step of releasing the low-molecular-weight substance from the porous carbon by mixing the porous carbon obtained after the adsorption step with an aqueous solution containing 0.1 mass % to 1 mass % of spherical silica having an average particle diameter of 10 nm to 100 nm and containing 10% to 12% of acetonitrile, or by causing the filtration filter to contact and pass through the aqueous solution.

Abstract: There is provided a method for quantitatively detecting 8-oxo 2?-deoxyguanosine in an aqueous sample solution with high sensitivity. A method for quantitatively detecting 8-oxo 2?-deoxyguanosine in an aqueous sample solution, including the steps of 1) immobilizing a fluorescent probe molecule showing a fluorescence response specific to 8-oxo 2?-deoxyguanosine on surfaces of fine particles via a spacer unit and bringing the sample solution into contact with the fine particles, and 2) measuring a physical property of the fine particles before and after the contact with the sample solution to determine a change in the physical property.

Abstract: There is provided a method for quantitatively detecting 8-oxo 2?-deoxyguanosine in an aqueous sample solution with high sensitivity. A method for quantitatively detecting 8-oxo 2?-deoxyguanosine in an aqueous sample solution, including the steps of 1) immobilizing a fluorescent probe molecule showing a fluorescence response specific to 8-oxo 2?-deoxyguanosine on surfaces of fine particles via a spacer unit and bringing the sample solution into contact with the fine particles, and 2) measuring a physical property of the fine particles before and after the contact with the sample solution to determine a change in the physical property.

Abstract: A biological evaluation method for rational and simply evaluating biological harmfulness or usefulness of a great number of natural and artificial chemicals, foods, etc. This method comprises adding a known amount of 2?-deoxyguanosine (dG) to a solution containing a test substance (drug, pesticide, functional food, etc.), optionally applying UV light and/or adding active oxygen generator, then quantifying 8-hydroxy-2?-deoxyguanosine (8OHdG) in the solution, and evaluating the toxicity or usefulness of the test substance according to the 8OhdG content (a higher 8OhdG content indicates a higher harmfulness of the test substance while a lower 8OhdG content indicates a lower harmfulness or an usefulness thereof). The invention also provide an apparatus for advantageously performing said biological evaluation method and an antioxidant preservative solution to be used in this apparatus.