Abstract: A method of purifying full length synthetic target oligonucleotides from a mixture of oligonucleotides, particularly from a mixture containing truncated or failed sequences is disclosed. The method involves attaching a short nucleotide sequence complementary to the 5' end of a target oligonucleotide to a solid support. The complementarity between the most 5' nucleotides of the target oligonucleotide and the bound oligonucleotide results in hybridization which serves to retain the target oligonucleotide. Truncated or failed sequences lacking 5' sequences complementary to the attached oligonucleotide, fail to hybridize and therefore are not retained. The method makes it possible to purify gram quantities of synthetic deoxyribonucleic acids or ribonucleic acids and sequences which have modifications, such as on the phosphate backbone. The support-bound nucleotide sequences are stable under conditions of purification and therefore can be reused.

Abstract: A method of site-directed alteration (removal or removal followed by replacement) of selected nucleotides in an RNA molecule, as well as to mixed phosphate backbone oligonucleotides useful in the method. It further relates to a method of producing polypeptides or proteins encoded by the RNA molecule altered by the present method. Through use of the present method, site-directed cleavage of an RNA molecule is effected, followed by excision of the selected or target segment of the RNA molecule.

Abstract: A method of inhibiting influenza virus replication through the activity of natural (unmodified) or modified oligonucleotides (oligodeoxynucleotides or oligoribonucleotides) which hybridize to a selected region of the influenza virus RNA and interfere with its ability to serve as a template for synthesis of encoded products. Oligonucleotides (unmodified or modified) which have antiviral activity against influenza virus as a result of their ability to hydridze to a selected region of influenza virus RNA and inhibit its ability to serve as a template for synthesis of encoded products, as well as compositions which include the oligonucleotides.

Abstract: A method of site-directed alteration (removal or removal followed by replacement) of selected nucleotides in an RNA molecule, as well as to mixed phosphate backbone oligonucleotides useful in the method. It further relates to a method of producing polypeptides or proteins encoded by the RNA molecule altered by the present method. Through use of the present method, site-directed cleavage of an RNA molecule is effected, followed by excision of the selected or target segment of the RNA molecule.

Abstract: A process of producing synthetic oligonucleotides on a small or large scale using H-phosphonate nucleoside monomers is described. The process can be used to synthesize oligonucleotides of any length, including oligodeoxyribonucleotides and oligoribonucleotides. The process results in a coupling efficiency of greater than 97% and consumes only two to three equivalents of monomer to activator per coupling reaction. In addition, the process does not require a separate capping step and capping reagent because the activating reagent serves a self-capping function thereby preventing elongation of failed sequences. The H-phosphonate linkages of the fully synthesized oligonucleotide can be oxidized with a variety of reagents to obtain either phosphate diester or other types of modified oligonucleotides.

Abstract: A component of blood platelets analogues thereof are described. The invention is based on the discovery that this component, a dinucleotide, as well as several of its chemically synthesized analogues, is an effective anti-platelet and antithrombotic agent.

Abstract: Inhibition of HTLV-III by adminstration of an oligonucleotide complementary to highly conserved regions of the HTLV-III genome necessary for HTLV-III replication and/or gene expression is described, as are oligodeoxynucleotide sequences which are complementary to those regions, methods of inhibiting HTLV-III replication and gene expression and methods of determining the presence or absence of HTLV-III virus in samples such as blood, saliva, urine and tears.