Modified nucleotides and polynucleotides and complexes form therefrom

A compound useful as a probe for detecting the presence or absence of a nucleic acid, said compound containing a nucleotide having the structure:

• ##STR28## wherein B represents a purine, 7-deazapurine, or pyrimidine moiety covalently bonded to the C.sup.1 '-position of the sugar moiety, provided that whenever B is purine or 7-deazapurine, the sugar moiety is attached at the N.sup.9 -position of the purine or deazapurine, and whenever B is a pyrimidine, the sugar moiety is attached at the N.sup.1 -position of the pyrimidine;
• wherein A represents at least three carbon atoms and an indicator molecule selected from the group consisting of fluorescent dyes, electron-dense reagents, enzymes which can be reacted with a substrate to produce a visually detectable reaction product and radioisotopes;
• wherein B and A are covalently attached directly or through a linkage group, said linkage group not interfering substantially with detection of A;
• wherein if B is a purine, A or the linkage group is attached to the 8-position of the purine, if B is a 7-deazapurine, A or the linkage group is attached to the 7-position of the deazapurine, and if B is a pyrimidine, A or the linkage group is attached to the 5-position of the pyrimidine;
• wherein one of x and y represents ##STR29## and the other of x and y is absent or represents --OH or --H;
• and wherein z represents H-- or HO--.

A complex useful as a probe for detecting the presence or absence of a nucleic acid, said complex comprising a detectable polypeptide complexed with a compound having the structure:

• ##STR30## wherein B represents a purine, 7-deazapurine, or pyrimidine moiety suitable for incorporation into a polynucleotide and covalently bonded to the C.sup.1 '-position of the sugar moiety, provided that when B is a purine or 7-deazapurine, the sugar moiety is attached at the N.sup.9 -position of the purine or deazapurine, and when B is pyrimidine, the sugar moiety is attached at the N.sup.1 position of the pyrimidine;
• wherein A represents at least three carbon atoms, is capable of specifically complexing with the detectable polypeptide when A is linked to B, and represents a component of a signalling moiety capable of producing a detectable signal;
• wherein B and A are covalently attached directly or through a linkage group, said linkage group not interfering substantially with the characteristic ability of A to form said complex with the detectable polypeptide;
• wherein if B is a purine, A is attached to the 8-position of the purine, if B is a 7-deazapurine, A is attached to the 7-position of the deazapurine, and if B is a pyrimidine, A is attached to the 5-position of the pyrimidine;
• and
• wherein each of x, y and z represents:
• ##STR31##

A complex useful as a probe for detecting the presence or absence of a nucleic acid, said complex comprising a detectable polypeptide complexed with an oligo- or polynucleotide containing a nucleotide having the structure:

• ##STR32## wherein B represents a purine, 7-deazapurine, or pyrimidine moiety covalently bonded to the C.sup.1 '-position of the sugar moiety, provided that whenever B is purine or 7-deazapurine, the sugar moiety is attached at the N.sup.9 -position of the purine or deazapurine, and whenever B is a pyrimidine, the sugar moiety is attached at the N.sup.1 -position of the pyrimidine;
• wherein A represents at least three carbon atoms, is capable of specifically complexing with the detectable polypeptide when A is linked to B, and represents a component of a signalling moiety capable of producing a detectable signal;
• wherein B and A are covalently attached directly or through a linkage group, said linkage group not interfering substantially with the characteristic ability of A to form said complex with the detectable polypeptide;
• wherein if B is a purine, A or the linkage group is attached to the 8-position of the purine, if B is a 7-deazapurine, A or the linkage group is attached to the 7-position of the deazapurine, and if B is a pyrimidine, A or the linkage group is attached to the 5-position of the pyrimidine;
• wherein one of x and y represents ##STR33## and the other of x and y is absent or represents --OH or --H;
• and wherein z represents H-- or HO--.