Patent ID: 7700287

Claim:
A method of sequencing a nucleic acid, comprising the steps of: a) forming a first, second, third, and fourth reaction mixture such that: (i) the first reaction mixture comprises a sequencing primer and a terminating nucleotide complementary to adenosine; (ii) the second reaction mixture comprises a sequencing primer and a terminating nucleotide complementary to cytosine; (iii) the third reaction mixture comprises a sequencing primer and a terminating nucleotide complementary to guanosine; and, (iv) the fourth reaction mixture comprises a sequencing primer and a terminating nucleotide complementary to thymidine or uridine; b) combining each of the first, second, third, and fourth reaction mixtures with a template polynucleotide, a polymerase, a mixture of nucleoside triphosphates suitable for enzymatic primer extension, and at least one blocking probe, wherein said template polynucleotide comprises, in a 3′ to 5′ direction, a priming sequence complementary to the sequencing primer, a sequence of interest, and a blocking sequence complementary to the blocking probe; c) enzymatically extending the sequencing primer in the first, second, third and fourth reaction mixtures to form a plurality of differently-sized primer extension products; d) separating the primer extension products based upon their sizes; and e) determining therefrom the sequence of the sequence of interest.