High sensitivity assay of sample nucleic acid fragment having complementarity using DNA analysis element or PNA analysis element

摘要

PROBLEM TO BE SOLVED: To perform determination with satisfactory sample reproducibility by fixing a large number of DNA fragments to a surface of a conductive substrate at one end and fixing chain molecules which have hydrophilic radicals at their one end or in their vicinities and can have cyclic radicals at midpoints at the other end or in its vicinity to the surface except the region limited to the DNA fragments. SOLUTION: An aqueous liquid formed by dissolving or dispersing DNA fragments is dripped to a surface of a conductive substrate and fixed by the amount of 100.20-100.12 mole par 1 mm of the surface of the conductive substrate at its one end. A solution is dripped to the surface of the conductive substrate to fix chain molecules via, for example, mercapto radicals. The solution contains a compound with mercapto radicals capable of combining chain molecules which have hydrophilic radicals (e.g. hydroxide radicals) at their one end or in their vicinities and can have cyclic radicals at midpoints to the surface of the conductive substrate at the hydrophilic radials and the other end or in their vicinities. The chain molecules are derived from, for example, 2- mercapto ethanol, 3-mercapto propanol, 6-mercapto hexanol, or the like.