Methods for simultaneous amplification of target loci
The invention provides methods for simultaneously amplifying multiple nucleic acid regions of interest in one reaction volume as well as methods for selecting a library of primers for use in such amplification methods. The invention also provides library of primers with desirable characteristics, such as minimal formation of amplified primer dimers or other non-target amplicons.
1. A method for preparing a deoxyribonucleic acid (DNA) fraction from a cancer patient useful for analyzing copy number variation and mutations of a cancer in a subject, comprising:
(a) collecting blood from the subject;
(b) extracting cell free DNA from the blood;
(c) producing a fraction of the DNA extracted in (b) by
(i) ligating adaptor tags and molecular barcodes to the extracted cell free DNA to generate barcoded DNA;
(ii) performing universal amplification using the adaptor tags to produce a sequencing library from the barcoded DNA;
(iii) enriching for a plurality of loci comprising 100-2,000 loci from the sequencing library using hybrid capture probes that target the plurality of loci;
(d) analyzing the cell free DNA in the fraction of DNA produced in (c) by
(i) performing massively parallel sequencing on the enriched plurality of loci to obtain sequence reads for the plurality of loci; and
(ii) determining the genetic state of the plurality of loci based on the sequence reads obtained from the massively parallel sequencing, wherein the possible genetic states comprise repeats and mutations, thereby detecting copy number variation and mutations of the cancer in the subject.
2. The method of claim 1 , wherein the plurality of loci comprises between 100 and 1,000 loci.
3. The method of claim 1 , wherein the plurality of loci comprises between 300 and 2,000 loci.
4. The method of claim 1 , wherein the molecular barcodes are not unique with respect to the cell free DNA to which they are attached.
5. The method of claim 1 , wherein the cell free DNA comprises mixed DNA from the cancer and from the host.
6. The method of claim 5 , wherein the method further comprises determining the fraction of DNA that is of cancer origin based on the sequence reads from the cancer DNA and the host DNA.
7. A method for preparing a deoxyribonucleic acid (DNA) fraction from a cancer patient useful for analyzing a ploidy state of a cancer in a subject, comprising:
(a) collecting a blood sample from the subject;
(b) extracting cell free DNA from the blood sample;
(c) producing a fraction of the DNA extracted in (b) by
(i) ligating adaptor tags and molecular barcodes to the extracted cell free DNA to generate barcoded DNA;
(ii) performing a universal amplification using the adaptor tags to produce a sequencing library from the barcoded DNA;
(iii) enriching a plurality of loci from the sequencing library using hybrid capture probes that target the plurality of loci;
(d) analyzing the cell free DNA in the fraction of DNA produced in (c) by
(i) performing massively parallel sequencing on the enriched plurality of loci to obtain sequence reads for the plurality of loci; and
(ii) determining the ploidy state of the cancer in the subject based on the sequence reads obtained from the massively parallel sequencing, wherein the plurality of loci comprises 300-2,000 loci.
8. The method of claim 7 , wherein the plurality of loci comprises between 300 and 1,000 loci.
9. The method of claim 7 , wherein the method further comprises determining mutations in the plurality of loci based on the sequence reads.
10. The method of claim 7 , wherein barcoded DNA from each targeted locus have a unique barcode.
11. The method of claim 9 , wherein the method further comprises determining the number of unique molecules in the blood sample for each locus based on sequence reads from the barcodes and the cell free DNA.
12. The method of claim 7 , wherein the molecular barcodes are not unique with respect to the cell free DNA to which they are attached.
13. The method of claim 7 , wherein the cell free DNA comprises mixed DNA from the cancer and from the host.
14. The method of claim 13 , wherein the method further comprises determining the fraction of DNA that is of cancer origin based on the sequence reads from the cancer DNA and the host DNA.