Patent ID: 7572578

Claim:
A method for isolating and purifying a nucleic acid, comprising the step of: (1) contacting a sample solution containing nucleic acid to a solid phase to adsorb the nucleic acid onto the solid phase; (2) contacting a washing solution to the solid phase to wash the solid phase in such a state that the nucleic acid is adsorbed; and (3) contacting an elution solution to the solid phase to desorb the nucleic acid, wherein the sample solution containing nucleic acid is prepared by further addition and mixing of a pretreatment solution containing an antifoaming agent and a surface-active agent, wherein the antifoaming agent is an alcohol-type antifoaming agent selected from at least one of the group consisting of: acetylene glycol, heptanol, and ethylhexanol, wherein the sample solution containing nucleic acid is prepared by further addition of a water-soluble organic solvent, wherein the solid phase is a porous membrane having an average pore diameter of 0.1 to 10.0 μm.