A process for preparing a derivative of an hydroxyl bearing substrate by reacting an hydroxyl bearing substrate with oxirane bearing molecules to produce an oxirane ring bearing substrate; and reacting the oxirane ring with a substituted primary aromatic amine selected from primary aromatic amine alcohols and primary aromatic amine thiols. Among the compositions so produced is a stable modified hydroxyl bearing substrate or hydroxyl bearing sheet having covalently bonded thereto primary aromatic amines which can be diazotized. The diazotized substrate selectively, covalently binds proteins, polypeptides, peptides, nucleic acids, RNA, single stranded DNA, and nucleic acid hybrids.

Improvements in the transfer and detection of separated nucleic acids, both RNA and DNA, are provided. For analysis of large DNA, the molecular weight segregated fractions of DNA are depurinated and fragmented to provide fractions having less than about 2 kb as single strands. With both RNA and DNA, the nucleic acid fractions are transferred after resolution to a chemically treated substrate and covalently affixed to the substrate. The resulting nucleotides affixed to the substrate are hybridized with labeled nucleotide probes and a volume exclusion agent, particularly a water soluble ionic polymer.

A process for production of a single strand of a nucleic acid comprising covalently linking to a solid substrate a polynucleotide complementary to the desired strand, hybridizing said polynucleotide with an oligonucleotide, extending the oligonucleotide in direction away from said substrate, denaturing the hybridized polynucleotide and extended oligonucleotide, thereby to free the extended oligonucleotide from the solid substrate, and separating the extended oligonucleotide. The product can be used for making analytical probes.

Novel compositions comprised of at least one bead conjugated to a solid support and further conjugated to at least one nucleic acid and preferred methods for making the novel compositions are described. As compared to "flat" surfaces, beads linked to a solid support provide an increased surface area for immobilization of nucleic acids. Furthermore, by selecting a bead with the desired functionality, a practitioner can select a functionalization chemistry for immobilizing nucleic acids, which is different from the chemistry of the solid support.

This invention encompasses diagnostic reagents comprising a polynucleic acid probe having a specific binding sequence and having one or more cytidines outside of the specific binding sequence. The polynucleic acid probe is bound to an amino functionalized solid support by a bisulfite mediated transamination between a cytidine and an amino group on the solid support. When the specific binding sequence contains cytidine, the cytidine is replaced with 5-methylcytidine which has essentially the same binding capacity and yet does not participate in transamination reactions. The invention encompasses compositions of the polynucleic acid probe as well as test kits including the above identified reagent and assays utilizing the above reagent. This invention is useful in detecting viruses, fungi and bacteria in test samples such as body fluids and food samples as well as detecting DNA or RNA sequences in mammalian cells.