The present invention provides an improved nucleic acid hybridization process employing a modified oligonucleotide probe comprising naturally occurring nucleotide bases. At least one nucleotide in the modified oligonucleotide is artificially mismatched relative to the control nucleic acid in addition to any mismatches arising from a variant nucleic acid target containing a sequence variation. The artificial mismatch and the sequence variation positions are separated from one another on the oligonucleotide by six to nine nucleotide positions.