Provided is a method of preparing at least one
ligation product from a sample including a plurality of single-strand
nucleic acid fragments, the method including the steps of: (a) ligating a first universal
oligonucleotide adaptor to at least one single-strand
nucleic acid fragment, wherein the first universal
oligonucleotide adaptor is configured for ligating to a 3′ end of individual single-strand
nucleic acid fragment; and (b) ligating a second universal
oligonucleotide adaptor to the at least one single-strand nucleic acid fragment, wherein the second universal oligonucleotide adaptor is configured for ligating to a 5′ end of individual single-strand nucleic acid fragment, thereby at least one
ligation product is formed. In another embodiment, provided is at least one
cancer biomarker comprising human
telomere sequence with two or more consecutive repeats of
nucleotide sequence TTAGGG.