Method combining single cell gene expression mapping and targeted rna or c-dna sequencing using padlock oligonucleotides comprising a barcode region

Abstract

Microscopy imaging that allow for multiple mRNAs to be resolved at a single cell level provides valuable information regarding transcript amount and localization, which is a crucial factor for understanding tissue heterogeneity, the molecular development and treatment of diseases. The current invention describes a method (Fly FISH) which combined the use of padlock oligonucleotides as fluorescence in situ hybridization (FISH) probes for detection and sequencing targeted portion of RNA or cDNA transcript at a cellular level with less limitation in the amount of transcripts and the length of the sequence that can be analyzed. Padlocks probes containing various barcodes in their core are utilized both as FISH probes and also to capture RNA portion that can be sequenced. The same barcodes can be used to selectively prime a rolling circle amplification and amplify a subset of transcripts coming from a specific region that have been tagged as of interest during the probing steps.