The invention is directed to modified oligonucleotide compositions and methods for selectively reducing unwanted nucleic acid contaminants and enriching for desired nucleic acid targets from complex genomic nucleic acid mixtures for sequencing applications. The modified oligonucleotide compositions include one or more modified groups that increase the T m of the resultant oligonucleotide composition.
1. A kit for use in a method for performing massively parallel sequencing of a desired template nucleic acid having a terminal adaptor, comprising:
a blocker oligonucleotide having a plurality of T m -enhancing groups, wherein the blocker oligonucleotide is an oligonucleotide selected from
(i) the group consisting of SEQ ID NOS: 2, 3, 4, 5, 6, 7 and 8;
(ii) the group consisting of SEQ ID NOS: 10, 11, 12, 13, 14, 15 and 16;
(iii) the group consisting of SEQ ID NOS: 18 and 19;
(iv) the group consisting of SEQ ID NOS: 21 and 22;
(v) the group consisting of SEQ ID NOS: 24 and 25;
(vi) the group consisting of SEQ ID NOS: 27 and 28;
(vii) SEQ ID NO: 30;
(viii) SEQ ID NO: 32,
(ix) SEQ ID NO: 34; and
(x) SEQ ID NO: 36, or a combination thereof.
2. The kit of claim 1 , wherein the terminal adaptor has a size range from 15 nucleotides to 75 nucleotides.
3. The kit of claim 1 , wherein the terminal adaptor includes a barcode domain.