UCLUST sort order
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11-Aug-2018 New paper describes octave plots for visualizing alpha diversity.

12-Jun-2018 New paper shows that one in five taxonomy annotations in SILVA and Greengenes are wrong.

18-Apr-2018 New paper shows that taxonomy prediction accuracy is <50% for V4 sequences.

05-Oct-2017 PeerJ paper shows low accuracy of closed- and open-ref. QIIME OTUs.

22-Sep-2017 New paper shows 97% threshold is wrong, OTUs should be 99% full-length 16S, 100% for V4.

UPARSE tutorial video posted on YouTube. Make OTUs from MiSeq reads.



UCLUST sort order

See also
  UCLUST algorithm
  Abundance sort

Sort order
UCLUST assumes that input sequences are sorted in an order such that an appropriate centroid sequence is found before other members of its cluster. The two most common sort orders are summarized in the table below.



Decreasing length

This order is most appropriate when both full-length sequences and fragments are present, as shown in the figure below.

However, with a length sort, the longest sequence may be an outlier.

Decreasing abundance

See abundance sorting.

Multiple alignment of a cluster.
The centroid (representative) sequence is shown in red.
Fragments are poor centroids because member sequences may be