Apparatus and methods for arraying solution onto a solid support

This invention relates to microfabrication technology, such as DNA chip-making technology, and more specifically to methods and apparatuses for delivering controlled amounts of a solution to specific, closely spaced locations on a solid support. A method for depositing biomolecule onto a solid support, the method including the steps of: immersing a tip of a spring probe into a solution of biomolecule; removing said tip from said solution to provide biomolecule solution adhered to said tip; and contacting said biomolecule solution with a solid support to thereby transfer biomolecule solution from said tip to said solid support. The spring probe has a planar tip but it otherwise identical to commercial spring probes. The solution of biomolecule contains a thickening agent in addition to biomolecule, where oligonucleotide is a preferred biomolecule.