Nucleic acid extraction device

An object of the present invention is to provide a nucleic acid extraction apparatus which extracts a nucleic acid from a specimen from which it has conventionally been considered difficult to extract the nucleic acid, such as feces or sludge, and thereby allows analysis in accordance with a PCR method (analysis using the polymerase chain reaction) to be performed successfully. The present invention includes a shaker ( 3 ), a centrifugal separator ( 5 ), a particle supply mechanism ( 8, 9 ) for supplying plural types of particles having different diameters, a liquid chemical supply mechanism ( 11 ) for supplying a liquid chemical, an arm ( 13, 14, 15 ) for conveying a specimen or a tube having therein the specimen, and control means ( 20 ). The control means ( 20 ) is constructed to perform a control operation for shaking the tube supplied with particles each having a large particle diameter and the specimen, putting the tube through the centrifugal separator ( 5 ) to separate a material containing a nucleic acid from the specimen, shaking the tube supplied with the separated material containing the nucleic acid, particles each having a small particle diameter, and the specimen, and putting the tube through the centrifugal separator ( 5 ) to crush the material containing the nucleic acid and extract the nucleic acid. In the nucleic acid extraction apparatus of the present invention having the foregoing structure, the nucleic acid is extracted by separating the material containing the nucleic acid (DNA) (e.g., a fungus body) from the specimen and crushing it. This allows easy and reliable extraction of the nucleic acid even from a specimen from which it has conventionally been considered difficult to extract the nucleic acid, such as feces, sludge, or the like.