Patent ID: 9518292
Filing Date: 2016-12-13
CPC Classification: C12Q

Claim Text:
1. A method of selectively amplifying one of two or more variants of a nucleic acid sequence in a nucleic acid sample, the method comprising: (a) hybridizing a forward selective primer to a nucleic acid sample comprising an amplification target sequence and a suppression target sequence, wherein the forward selective primer comprises: (i) a 3′ end priming sequence that is complementary to and hybridizes to a portion of the amplification target sequence and the suppression target sequence, and (ii) a 5′ end suppression sequence that is substantially identical to a portion of the suppression target sequence, wherein the portion of the suppression target to which the 5′ suppression sequence is substantially identical is 5′ of the portion of the suppression target sequence to which the 3′ end priming sequence hybridizes; (b) extending the hybridized forward selective primer of step (a) using a polymerase enzyme, the extension generating hybridized duplexes comprising: (i) the amplification target sequence and a hybridized complementary extension sequence, wherein the complementary extension sequence comprises, in the 5′ to 3′ direction, the forward selective primer and a sequence complementary to the amplification target sequence, and (ii) the suppression target sequence and a hybridized complementary extension sequence, wherein the complementary extension sequence comprises, in the 5′ to 3′ direction, the forward selective primer and a sequence complementary to the suppression target sequence; (c) denaturing the hybridized duplexes of step (b) to separate target sequences and complementary extension sequences; and (d) hybridizing a reverse primer to the complementary extension sequences of step (c), and extending the hybridized reverse primer using a 5′ to 3′ polymerase that lacks 5′ to 3′ exonuclease activity and substantially lacks strand displacement activity, wherein if the complementary extension sequence comprises the sequence complementary to the suppression target sequence, then amplification is suppressed by formation of a stem loop by the 5′ suppression sequence and a shorter amplification product is generated, and wherein if the complementary extension sequence comprises the sequence complementary to the amplification target sequence, then amplification is not suppressed by formation of a stem loop and a longer amplification product is generated,