US 7,517,978 B1
Modified oligonucleotides and applications thereof
Khairuzzaman Bashar Mullah, Union City, Calif. (US); Zhaochun Ma, San Carlos, Calif. (US); and Wanli Bi, San Ramon, Calif. (US)
Assigned to Applied Biosystems, LLC, Foster City, Calif. (US)
Filed on Oct. 12, 2005, as Appl. No. 11/250,192.
Application 11/250192 is a continuation of application No. 11/106021, filed on Apr. 14, 2005, abandoned.
Claims priority of provisional application 60/562388, filed on Apr. 14, 2004.
Int. Cl. C07H 21/04 (2006.01); C07H 21/02 (2006.01); C12Q 1/68 (2006.01); C12P 19/34 (2006.01)
U.S. Cl. 536—24.33  [536/23.1; 536/24.3; 435/6; 435/91.1; 435/91.2] 17 Claims
 
1. A polynucleotide primer effective in reducing primer-dimer formation comprising at least one modified purine nucleobase comprising the structure

OG Complex Work Unit Drawing
wherein R1 is selected from hydrogen, azido, nitro, unsubstituted or substituted amino, C1-C6 alkyl, and unsubstituted or substituted aryl,
at least one said modified purine nucleobase is no more than 3 nucleotides from the 3′ terminus of the primer, and the primer is extendable at its 3′-end, and
wherein the primer is effective in reducing primer-dimer formation.