DNA-containing ink composition
An ink, which contains DNA and is hardly decomposed by an external stimulus such as ultraviolet light, heat, an acid or an alkali, is provided. A method of easily analyzing a DNA in an ink composition is also provided. An ink composition containing a DNA and having a water-tolerance at a certain level or higher is prepared. The DNA in a print that is produced by using the above ink composition is quickly extracted with water or an aqueous solution and analyzed. Furthermore, a DNA in a print that is produced by using an oil- and water-based ink composition containing the DNA is quickly extracted with water or an aqueous solution and analyzed.
1. A waterproof DNA ink composition comprising water, titanium oxide, isopropanol, resin and a DNA wherein the content of the DNA is 50 pg to 100 ng per 1 ul of the ink composition.
2. The DNA ink composition according to claim 1 , wherein the resin is at least one selected from the group consisting of a urethane resin, an acrylic resin, and an epoxy resin.
3. A method of extracting a DNA from a print on a medium, which comprises the step of bringing a print, which is prepared using the DNA ink composition according to claim 1 , into contact with water or an aqueous solution.
4. The method according to claim 3 , wherein the medium is one selected from the group consisting of paper, a plastic resin, a fabric, a metal, and a food.
5. A method of judging the authenticity of a print on a medium, which comprises the steps of:
bringing a print, which is prepared using the ink composition according to claim 1 , into contact with water or an aqueous solution;
preparing an aqueous DNA-containing solution obtained by bringing the print into contact with water or an aqueous solution; and
analyzing the DNA in the aqueous DNA-containing solution prepared.
6. The method according to claim 5 , wherein the medium is one selected from the group consisting of paper, a plastic resin, a fabric, a metal, and a food.