Single-cell transcriptomics has revolutionised the study of cellular diversity and function by enabling gene expression analysis at single-cell resolution. The technique is crucial for understanding how different cells function, how they communicate, and how they contribute to various biological processes and diseases.
However, technical errors in the synthesis of oligonucleotides (short DNA sequences)—particularly in droplet-based methods such as Drop-seq and 10x Chromium—frequently lead to inaccurate results, causing researchers to discard valuable data. These synthesis errors obscure identification of the cell barcode (which identifies the cell) and UMI (unique molecular identifier) resulting in substantial data loss and limiting sequencing efficiency.
Published in Communications Biology, Associate Professor Adam Cribbs and Dr. Jianfeng Sun at the Botnar Institute for Musculoskeletal Sciences identified a major source of error: premature truncation of UMIs before sequencing. To address this, they developed a novel bead design that improves the reliability of gene expression measurements by mitigating truncation errors in UMIs prior to sequencing.
They added what they call an “anchor” between two important parts of the sequence: between the barcode and UMI. This anchor provides a clear demarcation point, enhancing UMI recognition and minimising synthesis errors.
The work builds on the Oxford team’s previous homotrimer UMI error correction strategy, which focused on errors arising after sequencing. In contrast, the new anchor-interposed approach tackles UMI errors at the pre-sequencing stage, further advancing long-read transcriptomics.