Patent ID: 8329887

Claim:
A kit for synthesizing first-strand cDNA molecules having a DNA sequence tag joined to their 3′-termini, the kit comprising: a terminal tagging oligoribonucleotide (rTTO), which rTTO comprises only ribonucleotides, with the exception of the 3′-terminal nucleotide, which 3′-terminal nucleotide is a 3′-modified ribonucleotide, a 3′-deoxyribonucleotide, a 2′,3′-dideoxyribonucleotide, or another nucleotide that is blocked so that it is not capable of being extended by a DNA polymerase, and which rTTO comprises a 5′-portion and 3′-portion, wherein (i) the 5′-portion exhibits a sequence complementary to the sequence of the DNA sequence tag that it is desired to join to the 3′-termini of first-strand cDNA molecules, and (ii) the 3′-portion comprises at least three random nucleotides, including the blocked 3′-terminal nucleotide; and an RNA-dependent DNA polymerase.