Method of immobilizing and stretching a nucleic acid on a substrate

A nucleic acid on a silicon substrate, which nucleic acid has been prepared by a method of immobilizing and stretching a nucleic acid on a substrate comprising:

• a) providing a silicon substrate,
• b) applying a solution of ammonium fluoride or of hydrogen fluoride onto a surface of said silicon substrate,
• c) allowing said solution of ammonium fluoride or hydrogen fluoride to remain on said surface of said silicon substrate for a defined period of time,
• d) applying an aqueous solution of a nucleic acid onto said surface of said silicon substrate,
• e) immobilizing said nucleic acid on said substrate and then elongating said nucleic acid by a process selected from the group consisting of molecular combing, spin-coating, application of a fluid flow, application of an electric field, application of convective forces in an evaporating droplet of said solution of said nucleic acid, and any combination of the aforementioned processes,
• wherein said method requires no chemical reagents to immobilize said nucleic acid on said substrate except for the treatment with ammonium fluoride or hydrogen fluoride,
• wherein, if a solution of ammonium fluoride is used, said solution of ammonium fluoride is an aqueous solution of NH4F, and
• wherein, if a solution of hydrogen fluoride is used, said solution of hydrogen fluoride is an aqueous solution of hydrogen fluoride.