The quality issues are currently under investigation, with evaluation of the raw sequence data underway. For some data sets, the read quality for the reverse read was not sufficient to allow paired-end read merging, suggesting that the reverse reads for an unknown number of runs may be unsuitable for analysis using the existing workflow. QC analysis of individual sequencing runs is underway and will be used to flag low-quality sequence data. Re-analysis of microbial community composition data products will begin after this analysis is complete. Thus far, no changes have been made to data available on the Data Portal. This issue will be updated again Feb 1, 2020.
