In one aspect the present invention provides methods of synthesizing a preparation of nucleic acid molecules, the methods comprising the steps of: (a) utilizing an RNA template to enzymatically synthesize a first DNA molecule that is complementary to at least 50 contiguous bases of the RNA template; (b) utilizing the first DNA molecule as a template to enzymatically synthesize a second DNA molecule, thereby forming a double-stranded DNA molecule wherein the first DNA molecule is hybridized to the second DNA molecule; (c) utilizing the first or second DNA molecule of the double-stranded DNA molecule as a template to enzymatically synthesize a first RNA molecule that is complementary to either the first DNA molecule or to the second DNA molecule; and (d) utilizing the first RNA molecule as a template to enzymatically synthesize a third DNA molecule that is complementary to the first RNA molecule. In another aspect, the present invention provides processed DNA samples prepared by a method of the invention for synthesizing a preparation of nucleic acid molecules. In another aspect, the present invention provides methods for hybridizing a processed DNA sample to a population of immobilized nucleic acid molecules.