Abstract Biological tissues contain thousands of different proteins yet conventional antibody staining can only assay a few at a time because of the limited number of spectrally distinct fluorescent labels. The capacity to map the location of hundreds or thousands of proteins within a single sample would allow for an unprecedented investigation of the spatial proteome, and give insight into the development and function of diseased and healthy tissues. In order to achieve this goal, we propose a new technology that leverages established methodologies for in situ imaging of nucleic acids to achieve near limitless multiplexing. The exponential scaling power of DNA technologies ties multiplexing to the number of DNA nucleotides sequenced rather than the number of spectrally distinct labels. Here we demonstrate that barcode sequencing can be applied to in situ proteomics by sequencing DNA conjugated antibodies bound to biological samples. In addition, we show a signal amplification method which is compatible with barcoded antibodies.

Fluorescent in situ sequencing of DNA barcoded antibodies