| abstract |
(57) [Summary] [Object] To extract a nucleic acid from a biological material, to extract and purify the nucleic acid in a simple, rapid and highly purified manner, and to provide a method capable of decantation or inversion fractionation. [Structure] After performing pretreatment for eluting nucleic acids from biological materials, a nonhydrophilic high-density organic liquid containing a thixotropic thickening agent and an aqueous liquid are added to the pretreated biological materials and mixed. Then, after centrifugation, a non-fluidic aggregation layer is formed on the interface between the upper layer and the lower layer to easily separate the upper layer containing the nucleic acid and extract the nucleic acid. |