Methods and Kits for Detecting Nucleic Acid Mutants in Wild-Type Populations

Abstract

This disclosure relates to amplification and detection of a rare variant or variants of a DNA sequence in an abundant variant of the sequence, such as detection of a low-level somatic mutations and minority alleles in an excess of normal nucleic acid target sequences.

We claim: 
     
         1 - 17 . (canceled) 
     
     
         18 . A kit of reagents for selectively amplifying a rare second variant of a target sequence that differs from a first variant of the target sequence by at least one nucleotide, the kit comprising a primer-blocking hairpin oligonucleotide, a first and a second linear amplification primers that bracket the target sequence, and amplification reagents, wherein the primer-blocking hairpin oligonucleotide has a binding site on the target sequence downstream from the binding site of the first linear amplification primer that includes the at least one nucleotide difference. 
     
     
         19 . The kit of  claim 18 , wherein the second amplification primer is mismatched to the target sequence. 
     
     
         20 . The kit according to  claim 18  wherein the first and second primers are tailed primers. 
     
     
         21 . The kit according to  claim 20  wherein at least one primer is a flip-tail primer.