Cited by 10,488Single-cell and spatial transcriptomicsGene expression and cancer classificationGene Regulatory Network Analysis

Fast, sensitive and accurate integration of single-cell data with Harmony

Open access
Korsunsky, Ilya, Millard, Nghia, Fan, Jean, Slowikowski, Kamil, Zhang, Fan, Wei, Kevin, Baglaenko, Yuriy, Brenner, Michael +2 more·2019·Nature Methods

Published version of a preprint

Abstract

The emerging diversity of single-cell RNA-seq datasets allows for the full transcriptional characterization of cell types across a wide variety of biological and clinical conditions. However, it is challenging to analyze them together, particularly when datasets are assayed with different technologies, because biological and technical differences are interspersed. We present Harmony (https://github.com/immunogenomics/harmony), an algorithm that projects cells into a shared embedding in which cells group by cell type rather than dataset-specific conditions. Harmony simultaneously accounts for multiple experimental and biological factors. In six analyses, we demonstrate the superior performance of Harmony to previously published algorithms while requiring fewer computational resources. Harmony enables the integration of ~10 6 cells on a personal computer. We apply Harmony to peripheral blood mononuclear cells from datasets with large experimental differences, five studies of pancreatic islet cells, mouse embryogenesis datasets and the integration of scRNA-seq with spatial transcriptomics data.

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Integrity signals

Registry

Crossref · 10.1038/s41592-019-0619-0

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  • Both Harmony's and scVI's design inherently incorporates batch labels in its training process.

    “Importantly, both Harmony’s and scVI’s design inherently incorporates batch labels in its training process.”

    From Zero-shot evaluation reveals limitations of single-cell foundation models (2025) · cites this paper as [21]

    The Online Methods > Harmony overview (page unavailable) states that Harmony takes batch assignments as input, and its algorithm uses them during clustering and correction. The copy does not establish the claim about scVI’s design or training process; a search for “scVI” found no relevant passage. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Multi-omics integration is a natural application area where specialized agents analyze transcriptomic, epigenomic, proteomic, and spatial datasets, reconciling heterogeneous signals through shared representation spaces.

    “Multi-omics integration represents another natural application area, where specialized agents analyze transcriptomic, epigenomic, proteomic, and spatial datasets, reconciling heterogeneous signals through shared representation spaces, a task particularly suited to foundation models capable of cross-modal alignment [12, 43, 44].”

    From The next paradigm in bioinformatics: a review of multi-agent systems and foundational models for end-to-end scientific discovery (2026) · cites this paper as [44]

    The Abstract says Harmony projects cells into a shared embedding, and the Results section demonstrates integration of transcriptomic and spatially resolved datasets. Our copy does not support the claim that specialized agents analyze epigenomic or proteomic datasets, or that Harmony integrates those modalities. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • ModuleEigengenes can optionally employ the harmony algorithm following SVD, which increases runtime but not memory usage.

    “Optionally, ModuleEigengenes can employ the harmony22 algorithm following SVD, which increases runtime but not memory usage.”

    From hdWGCNA identifies co-expression networks in high-dimensional transcriptomics data (2023) · cites this paper as [22]

    The Online Methods > Harmony section (page not provided) describes Harmony operating on a PCA embedding, supporting its use after dimensionality reduction. The Results > Harmony Scales to Large Data section reports Harmony’s runtime and memory usage, but does not assess its use in ModuleEigengenes or show that adding it increases runtime without increasing memory usage. (LLM, conf=0.85)

    Experimental — accuracy not yet measured
  • Batch effects between samples were corrected using harmonypy on the scaled topic distributions.

    “Batch effects between samples were corrected using harmonypy89 (v0.0.6) on the scaled topic distributions, and Leiden clustering with resolution 0.6 resulted in 11 clusters, corresponding to 14 cell types based on previous labelling.”

    From Enhancer grammar of liver cell types and hepatocyte zonation states (2022) · cites this paper as [89]

    The Online Methods > Harmony section describes an algorithm that corrects batch effects in cell embeddings, supporting the citation for the batch-correction method. Our copy identifies an R implementation, however, not harmonypy or version 0.0.6; it also does not describe correction of scaled topic distributions. No page number is available in our copy. (LLM, conf=0.83)

    Experimental — accuracy not yet measured
  • Harmony batch correction was used to correct PCA embeddings for technical batch effects between experiments.

    “Harmony batch correction was then used to correct PCA embeddings for technical batch effects between experiments 54 .”

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Authors
Korsunsky, I., Millard, N., Fan, J., Slowikowski, K., Zhang, F., Wei, K., Baglaenko, Y., Brenner, M., Loh, P.-R., & Raychaudhuri, S.
Affiliations
  • Broad Institute (US)
  • Harvard University (US)
  • Brigham and Women's Hospital (US)
Corresponding author
Raychaudhuri, Soumya
Venue
Nature Methods
Published
2019-11-18
Volume
16
Issue
12
Pages
1289-1296
ISSN
  • 1548-7091 (ISSN-L)
  • 1548-7105
OpenAlex
W2984472267
Cited by
10,488
References
57
Citations by year
2026: 2634 · 2025: 2714 · 2024: 2218 · 2023: 1370 · 2022: 845 · 2021: 464 · 2020: 196 · 2019: 37 · 2014: 1
FWCI
131.99
Type
journal article
Language
en
Open access
Locations
  • Nature Methods (publishedVersion)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • U.S. Department of Health & Human Services | National Institutes of Health (UH2AR067677, U19AI111224, T32 AR007530-31)
  • F. Hoffmann-La Roche Ltd
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Single-cell and spatial transcriptomics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gene expression and cancer classification
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gene Regulatory Network Analysis
Keywords
single-cell RNA sequencing, multi-omics integration, harmony, cell type clustering, peripheral blood mononuclear cells, pancreatic islet cells, mouse embryo development, spatial transcriptomics, computational efficiency
MeSH terms
Algorithms, Animals, Base Sequence, Humans, Jurkat Cells, Mice, HEK293 Cells, Single-Cell Analysis, Datasets as Topic

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