An aptamer comprising: a first sequence comprising SEQ ID NO:1 or a variant thereof or SEQ ID NO:2 or a variant thereof, a second sequence comprising SEQ ID NO:3 or a variant thereof, a third sequence comprising SEQ ID NO:1 or a variant thereof or SEQ ID NO:2 or a variant thereof, and a fourth sequence comprising SEQ ID NO:3 or a variant thereof, wherein each of the first and third sequences are 14-18 nucleotides in length, are equal in length to each other, and are 100% complementary to each other along their entire length; and wherein the second and fourth sequences are 12 nucleotides in length and are identical to each other; wherein the variant of SEQ ID NO:1 comprises 1, 2, 3 or 4 nucleotide substitutions; and the variant of SEQ ID NO: 3 comprises 1 or 2 nucleotides substitutions; and wherein: there is no covalent bond between 2 of the nucleotides within the first sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, or there is no covalent bond between 2 of the nucleotides within the third sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, wherein the aptamer inhibits the activity of a thermostable polymerase. a first sequence comprising SEQ ID NO:1 or a variant thereof or SEQ ID NO:2 or a variant thereof, a second sequence comprising SEQ ID NO:3 or a variant thereof, a third sequence comprising SEQ ID NO:1 or a variant thereof or SEQ ID NO:2 or a variant thereof, and a fourth sequence comprising SEQ ID NO:3 or a variant thereof, wherein each of the first and third sequences are 14-18 nucleotides in length, are equal in length to each other, and are 100% complementary to each other along their entire length; and wherein the second and fourth sequences are 12 nucleotides in length and are identical to each other; wherein the variant of SEQ ID NO:1 comprises 1, 2, 3 or 4 nucleotide substitutions; and the variant of SEQ ID NO: 3 comprises 1 or 2 nucleotides substitutions; and wherein: there is no covalent bond between 2 of the nucleotides within the first sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, or there is no covalent bond between 2 of the nucleotides within the third sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, wherein the aptamer inhibits the activity of a thermostable polymerase. the variant of SEQ ID NO:1 comprises 1, 2, 3 or 4 nucleotide substitutions; and the variant of SEQ ID NO: 3 comprises 1 or 2 nucleotides substitutions; and wherein: there is no covalent bond between 2 of the nucleotides within the first sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, or there is no covalent bond between 2 of the nucleotides within the third sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, wherein the aptamer inhibits the activity of a thermostable polymerase. there is no covalent bond between 2 of the nucleotides within the first sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, or there is no covalent bond between 2 of the nucleotides within the third sequence and wherein the aptamer comprises a 5' terminus and a 3' terminus, wherein the aptamer inhibits the activity of a thermostable polymerase.