| 摘要 |
<p>Nucleic acid probe assay methods, particularly sandwich assay methods, and compositions for use therein. The methods of the invention employ novel, oligonucleotide probe-derivatized solid supports, in which oligonucleotide probe, of 15-100 bases in a sequence complementary to a sequence of nucleic acid analyte, is terminally covalently bound. The solid supports of the invention are based on beads of amino-, sulfhydryl, or carboxyl-derivatized controlled pore glass, cyanogen bromide-treated cross-linked dextran, or polystyrene. The linkage between the terminally bound oligonucleotide and the support is effected through these groups, with which the support material is derivatized. The methods of the invention are based on several unexpected discoveries made in the course of investigating the properties of the novel solid supports of the invention: (A) There is little difference between carrying out a sandwich assay by (i) simultaneously hybridizing analyte to solid-support-bound probe and labeled probe in solution and (ii) first hybridizing analyte and labeled probe and then hybridizing analyte to solid support-bound probe. (B) The efficiency of capture of analyte is increased by prehybridizing probe-derivatized solid-support with non-homologous nucleic acid or dextran sulfate or both. (C) The presence of dextran sulfate in a hybridizing solution significantly increases the efficiency of capture of analyte by probe-derivatized solid support. The invention also entails test kits for nucleic acid probe sandwich assays with the solid supports of the invention.</p> |
