Abstract: A process for crosslinking polynucleotide molecules that includes (1) providing a plurality of first nucleic acids, a plurality of second nucleic acids, and a plurality of third nucleic acids, in which each of the first nucleic acids, complementary to each of the second nucleic acids, contains a sequence which is complementary to a site of each of the third nucleic acids, and the number of the first nucleic acids and that of the second nucleic acids are each 1 to 1016 times that of the third nucleic acids; and (2) denaturing and localizing the pluralities of nucleic acids to a planar surface to facilitate formation of a crosslinked nucleic acid complex. Also disclosed is a solvent system, which includes a hydrophobic organic solvent and a chaotropic aqueous solvent, for conducting the above-described process.