Rxivist logo

Enhancing droplet-based single-nucleus RNA-seq resolution using the semi-supervised machine learning classifier DIEM

By Marcus Alvarez, Elior Rahmani, Brandon Jew, Kristina M. Garske, Zong Miao, Jihane N Benhammou, Chun Jimmie Ye, Joseph R. Pisegna, Kirsi H Pietiläinen, Eran Halperin, Päivi Pajukanta

Posted 30 Sep 2019
bioRxiv DOI: 10.1101/786285 (published DOI: 10.1038/s41598-020-67513-5)

Single-nucleus RNA sequencing (snRNA-seq) measures gene expression in individual nuclei instead of cells, allowing for unbiased cell type characterization in solid tissues. Contrary to single-cell RNA seq (scRNA-seq), we observe that snRNA-seq is commonly subject to contamination by high amounts of extranuclear background RNA, which can lead to identification of spurious cell types in downstream clustering analyses if overlooked. We present a novel approach to remove debris-contaminated droplets in snRNA-seq experiments, called Debris Identification using Expectation Maximization (DIEM). Our likelihood-based approach models the gene expression distribution of debris and cell types, which are estimated using EM. We evaluated DIEM using three snRNA-seq data sets: 1) human differentiating preadipocytes in vitro , 2) fresh mouse brain tissue, and 3) human frozen adipose tissue (AT) from six individuals. All three data sets showed various degrees of extranuclear RNA contamination. We observed that existing methods fail to account for contaminated droplets and led to spurious cell types. When compared to filtering using these state of the art methods, DIEM better removed droplets containing high levels of extranuclear RNA and led to higher quality clusters. Although DIEM was designed for snRNA-seq data, we also successfully applied DIEM to single-cell data. To conclude, our novel method DIEM removes debris-contaminated droplets from single-cell-based data fast and effectively, leading to cleaner downstream analysis. Our code is freely available for use at <https://github.com/marcalva/diem>.

Download data

  • Downloaded 651 times
  • Download rankings, all-time:
    • Site-wide: 39,265
    • In bioinformatics: 4,276
  • Year to date:
    • Site-wide: 68,932
  • Since beginning of last month:
    • Site-wide: 56,519

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide