RT Journal Article SR Electronic T1 Squeegee: de-novo identification of reagent and laboratory induced microbial contaminants in low biomass microbiomes JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.05.06.442815 DO 10.1101/2021.05.06.442815 A1 Yunxi Liu A1 R. A. Leo Elworth A1 Michael D. Jochum A1 Kjersti M. Aagaard A1 Todd J. Treangen YR 2021 UL http://biorxiv.org/content/early/2021/05/07/2021.05.06.442815.abstract AB Computational analysis of host-associated microbiomes has opened the door to numerous discoveries relevant to human health and disease. However, contaminant sequences in metagenomic samples can potentially impact the interpretation of findings reported in microbiome studies, especially in low biomass environments. Our hypothesis is that contamination from DNA extraction kits or sampling lab environments will leave taxonomic “bread crumbs” across multiple distinct sample types, allowing for the detection of microbial contaminants when negative controls are unavailable. To test this hypothesis we implemented Squeegee, a de novo contamination detection tool. We tested Squeegee on simulated and real low biomass metagenomic datasets. On the low biomass samples, we compared Squeegee predictions to experimental negative control data and show that Squeegee accurately recovers known contaminants. We also analyzed 749 metagenomic datasets from the Human Microbiome Project and identified likely previously unreported kit contamination. Collectively, our results highlight that Squeegee can identify microbial contaminants with high precision. Squeegee is open-source and available at: https://gitlab.com/treangenlab/squeegeeCompeting Interest StatementThe authors have declared no competing interest.