Chimeras of sulfur-linked oligonucleotide analogs and DNA and RNA

An oligonucleotide analog comprising at least one building subunit of the formula

• wherein n is an integer less than 25, V is independently selected from —O— or —CH2—, Q is independently selected from the group consisting of —H and —OH, W is independently selected from the group consisting of —S—, —S(O)—, and —S(O2)—, and each B is independently selected from the group consisting of adenine, 7-deazaadenine, 7-deaza-8-azaadenine, 3,7-dideazaadenine, 8-deazaadenine, guanine, 3-deazaguanine, 7-deaza-8-azaguanine, 3,7-dideazaguanine, 3,7-dideaza-8-azaguanine, 7-deazaguanine, 8-azaguanine, purine, azapurine, 2,6-diaminopurine, hypoxanthine, uracil, 5-azauracil, 6-azauracil, 5-fluorouracil, 5-bromouracil, 5-iodouracil, thymine, 6-azathymine, cytosine, 6-azacytosine, 5-azacytosine, pyrimidine, azapyrimidine, pyrrolopyrimidine, pyrazolopyrimidine, triazolopyrimidine, imidazolopyrimidine, pyridine, imidazolopyridine, pyrrolopyridine, pyrazolopyridine, triazolopyridine, and the the structural formulae below, wherein —R designates the point of attachment of the base to position 1 of a ribose or deoxyribose ring, X is either a nitrogen atom or a carbon atom bearing a substituent Z, Z is either a hydrogen, an unfunctionalized lower alkyl chain, or a lower alkyl chain bearing an amino, carboxyl, hydroxy, thiol, aryl, indole, or imidazoyl group, Y is either N or CH, and the ring contains no more than three nitrogens consecutively bonded.