Spatial molecular barcoding of in situ nucleic acids

1. A method of processing a sample, comprising:

(a) indirectly or directly attaching nucleic acid tags to binding sites in a planar cellular sample;

(b) contacting the planar cellular sample with a solid support comprising an array of spatially addressed features that comprise oligonucleotides, wherein each oligonucleotide comprises a molecular barcode that identifies the location of the oligonucleotide on the solid support and wherein the array is made by

(i) synthesizing the oligonucleotides on a solid support, and

(ii) cleaving the oligonucleotides from the solid support in the gas phase,

to produce an array of oligonucleotides that are spatially addressed but not attached to the support;

(c) hybridizing the nucleic acid tags, or a copy of the same, with said oligonucleotides to produce duplexes; and

(d) extending the oligonucleotides in said duplexes to produce extension products that each comprises (i) a molecular barcode and (ii) a copy of a nucleic acid tag or a complement thereof.

2. The method of claim 1 , further comprising:

(e) amplifying the extension products by PCR to produce amplification products.

3. The method of claim 2 , further comprising:

(f) sequencing the amplification products to obtain, for each sequenced amplification product, the sequence of a molecular barcode and the sequence of a nucleic acid tag.

4. The method of claim 3 , further comprising:

(g) constructing an image of the planar cellular sample showing the binding sites for the attached nucleic acid tags, wherein, for each sequenced extension product, the molecular barcode provides spatial coordinates for the associated nucleic acid tag.

5. The method of claim 4 , wherein the image shows the position and abundance of the attachment sites for the nucleic acid tags.

6. The method of claim 1 , wherein said nucleic acid tags are attached to antibodies.

7. The method of claim 1 , wherein said nucleic acid tags are RNA or DNA aptamers.

8. The method of claim 1 , wherein said nucleic acid tags are the product of a proximity ligation assay.

9. The method of claim 1 , wherein the oligonucleotides have two or more sections separated by cleavable linkages, wherein at least one of the sections comprises said molecular barcode and the sections, when they are cleaved from the array, provide PCR primers that amplify the nucleic acid tags.

10. The method of claim 1 , wherein the oligonucleotides comprise one or more repeats of a sequence of formula X-Y, wherein X is the molecular barcode and Y hybridizes to the nucleic acid tags or the complement thereof.

11. The method of claim 1 , wherein the method comprises (i) copying the nucleic acid tags and (ii) hybridizing the copy of the nucleic acid tags with said oligonucleotides to produce duplexes.

12. The method of claim 1 , further comprising registering the constructed image with an image of the original planar cellular sample.

13. The method of claim 12 , wherein the registering is assisted by register features that were added to the planar cellular sample prior to analysis.

14. The method of claim 1 , wherein said nucleic acid tags or said oligonucleotides are attached to magnetic beads.

15. The method of claim 1 , wherein said planar cellular sample is an FFPE tissue section.

16. The method of claim 15 , wherein said tissue section is a tissue biopsy.

17. The method of claim 1 , wherein the method comprises indirectly or directly attaching a plurality of different nucleic acid tags to sites in a planar cellular sample, wherein different tags are attached to a plurality of binding agents designed to bind to two or more classes of target molecules, said classes comprising DNA, RNA, proteins, oligosaccharides, and lipids.