Method of amplifying and detecting nucleic acid sequences

A method for detecting point mutations in nucleic acid template and amplifying at least one specific nucleic acid sequence contained in a sample of nucleic acid template wherein each nucleic acid consists of either one strand or two separate complementary strands, comprising treating the strands with at least one of two sets of two different relatively short oligonucleotides each of which sets (i) is complementary to and therefore will hybridize to at least a portion of the template sequence of at least one of the strands and (ii) flanks both sides of a designated target base contained within the specific nucleic acid sequence, such that one of the two short oligonucleotides in each set of oligonucleotides contains a base at one of its ends that is complementary to one of the target bases of said template under conditions such that the two short oligonucleotides of each of the sets will mutually ligate if the target base pair exists in the template, the ligation occurring between the terminal base of one of the complementary oligonucleotides which is complementary to one of the target bases and a terminal base of another complementary oligonucleotide of the same set.