Polynucleotide barcoding
View Patent ↗A polynucleotide is barcoded using a method whereby an isolated, individual polynucleotide is immobilized on a solid phase and stretched, targets are labeled using target-specific hybridization probes, and an individual label of an unamplified probe at each of the labeled targets is optically detected. The order of the labels is determined to form a barcode representation of the polynucleotide wherein the targets and their relative positions are represented.
1. A method for barcoding a polynucleotide, comprising the steps of:
a) immobilizing on a solid phase and stretching an isolated, individual polynucleotide comprising nucleotide targets;
b) labeling each of the targets using a corresponding target-specific hybridization probe; and
c) directly optically detecting a single, individual fluorescent label of each unamplified probe at each of the targets, and determining label order to form a barcode representation of the polynucleotide wherein the targets and their relative positions are represented,
wherein in the labeling step, discontinuous padlock probes are hybridized to the targets, and gap-filled with fluorescent nucleotides.
2. The method of claim 1 wherein in the labeling step, discontinuous padlock probes are hybridized to the targets, and gap-filled with fluorescent nucleotides, and wherein a first fluorophore is used to label a subset of nucleotides A, T, G, and C; and a second fluorophore is used to label the remaining nucleotides.
3. The method of claim 1 wherein in the labeling step, discontinuous padlock probes are hybridized to the targets and gap-filled with fluorescent nucleotides, and wherein a distinct fluorophore is used to label each of nucleotides, A, T, G, and C.
4. The method of claim 1 wherein the polynucleotide comprises SNP alleles of a haplotype, the targets are the alleles, and the barcode represents the haplotype.
5. The method of claim 1 wherein the polynucleotide comprises SNP alleles of a haplotype, the targets are the alleles, the barcode represents the haplotype, and wherein the labeling step comprises using a distinct fluorophore to label each of a common and a minor polymorphism of each of the alleles.
6. The method of claim 1 further comprising the step of end-labeling the polynucleotide.
7. The method of claim 1 additionally comprising, prior to the detecting step, labeling the polynucleotide with a sequence non-specific dye.
8. The method of claim 1 additionally comprising, prior to the detecting step, labeling the polynucleotide with a sequence non-specific dye, wherein the detecting step comprises determining the ratio of intensity of the dye on one side of a labeled target to the total dye intensity to provide a position of the labeled target as a fraction of the total length of the polynucleotide.
9. The method of claim 1 wherein the detecting step further comprises measuring the distance between each labeled target, to form a barcode representation of the polynucleotide, wherein the distances between the targets are represented.
10. The method of claim 1 wherein the detecting step comprises using total internal reflection (TIR) microscopy and imaging fluorescence emission with a charge-coupled device (CCD) camera.
11. The method of claim 1 wherein the detecting step comprises Fluorescence Imaging with One Nanometer Accuracy (FIONA).
12. The method of claim 1 wherein the detecting step comprises single-molecule high-resolution imaging with photobleaching (SHRImP).
13. The method of claim 1 wherein adjacent targets are separated by less than 1000 bases, and wherein the detecting step comprises single-molecule high-resolution imaging with photobleaching (SHRImP).