Method for preparing sample, solution for preparing sample and stool collection kit method for analyzing a nucleic acid

A solution for preparing a sample, comprising:

• one or more members selected from the group consisting of a polycation and a chelating agent as an active ingredient,
• wherein the solution is used for recovering a nucleic acid from the nucleic acid-containing sample.

A method for analyzing a nucleic acid comprising:

• (i) preparing a prepared sample by mixing a nucleic acid-containing sample with a solution for preparing a sample having one or more members selected from the group consisting of a polycation and a chelating agent as an active ingredient,
• (ii) recovering a nucleic acid from a cell contained in the prepared sample prepared in the step (i), and
• (iii) analyzing the nucleic acid recovered in the step (ii).

A method for analyzing a nucleic acid, comprising:

• conducting reverse transcriptase reaction or nucleic acid chain elongation reaction in a reaction solution containing a polycation.

A method for recovering nucleic acid from a stool, comprising:

• simultaneously recovering a nucleic acid derived from indigenous intestinal bacterium and a nucleic acid derived from an organism other than indigenous intestinal bacterium, from the stool sample, and
• the stool sample is prepared by mixing a collected stool with a solution for preparing a sample having one or more members selected from the group consisting of a polycation and a chelating agent as an active ingredient.