Matrix-seq: An adjustable-resolution spatial transcriptomics via microfluidic matrix-based barcoding.

Spatial transcriptomics technology complements the spatial information lost in single-cell RNA sequencing, which enables visualization and quantitative analysis of transcriptomics of cells in tissue sections. Although this technology is a promising tool to study complex biological processes, its popularization is limited by cumbersome barcoding steps. We presented a microfluidics-based barcoding strategy called Matrix-seq, which gets rid of both precision instruments and the in situ indexing. The deterministic barcoding matrix is fabricated by the crossflow of Barcode-X and Barcode-Y. The overlapping areas (spot) formed deterministic barcoding primers (Barcode-X-Y) via the ligation reaction. Matrices with different spot size (ranging from 10 to 50 m), which was decided by the width of microchannels, were fabricated and then applied to a mouse main olfactory bulb section and a mouse brain section. While maintaining high performance and resolution, this technology greatly reduces the technical threshold and cost of spatial barcoding. As a result, Matrix-seq can be rapidly applied in various fields including developmental biology, neuroscience and clinical pathology. TeaserMatrix-seq provides an orthogonal microchannel-based barcoding strategy for adjustable-resolution spatial transcriptomics.