Fullscope-seq Maps Transcript Isoforms with Spatial Single-Cell Resolution

Fullscope-seq is a new sequencing method that maps transcript isoforms with spatial single-cell resolution, according to reporting by Drug Target Review on July 31, 2026. This technology allows researchers to identify specific variations of RNA molecules—known as isoforms—while maintaining the exact physical location of the cells within a tissue sample.

Most existing spatial transcriptomics tools provide a general count of gene expression but struggle to distinguish between different isoforms of the same gene. Because different isoforms can perform vastly different functions within a cell, the ability to map them spatially helps scientists understand how tissue architecture influences gene regulation and disease progression.

Technical Capabilities of Fullscope-seq

The Fullscope-seq method addresses a primary limitation in single-cell sequencing: the loss of spatial context. According to Drug Target Review, the process enables the detection of full-length transcripts, which is necessary to identify the exact splicing patterns that create distinct isoforms.

By combining single-cell resolution with spatial mapping, the tool allows researchers to see not only which genes are active in a specific cell but also which specific version of the protein that gene is likely to produce. This level of detail is critical for studying complex tissues like the brain or tumors, where the location of a cell often dictates its function.

Impact on Drug Discovery and Disease Research

The mapping of transcript isoforms is a key factor in identifying new drug targets. According to the analysis in Drug Target Review, many diseases are driven by “pathogenic isoforms”—versions of a transcript that appear only in diseased tissue or are located in specific regions of a tumor.

Standard bulk sequencing averages the RNA content of thousands of cells, which can mask these rare but critical isoforms. Fullscope-seq prevents this by isolating the signal to the individual cell level and its specific coordinate within the organ or tissue. This allows for the identification of targets that are spatially restricted, potentially reducing off-target effects in drug development.

Comparison with Traditional Spatial Transcriptomics

Traditional spatial transcriptomics often rely on short-read sequencing or targeted probes. According to the technical details provided by Drug Target Review, these methods frequently miss the full structure of the RNA transcript, making it difficult to confirm the exact isoform present.

Fullscope-seq differs by capturing the full-length transcript. This provides a more complete picture of the cellular state compared to methods that only provide a “snapshot” of gene expression levels without the structural context of the RNA.

Current Limitations and Future Applications

While the method provides high resolution, the implementation of full-length sequencing at a spatial scale remains technically demanding. The data generated by Fullscope-seq requires significant computational power to align isoforms to their correct spatial coordinates and genomic origins.

Researchers intend to use this tool to map the “isoformome” of various human tissues. This effort aims to create a reference map of how isoforms are distributed across healthy and diseased organs, which may lead to more precise diagnostic biomarkers for oncology and neurology.