# singletons

**URL:** <https://forum.mothur.org/t/singletons/3441>\
**Category:** Commands in mothur\
**Created:** [November 10, 2017, 6:20am UTC](https://forum.mothur.org/t/singletons/3441 "2017-11-10T06:20:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![xvazquezc](https://avatars.discourse-cdn.com/v4/letter/x/838e76/32.png) [@xvazquezc](https://forum.mothur.org/u/xvazquezc)\
**Post date:** [November 10, 2017, 6:20am UTC](https://forum.mothur.org/t/singletons/3441/1 "2017-11-10T06:20:36Z")

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Hi there,

I was looking for info about the best way to remove singletons (and best time to do it in the workflow) but I saw this in [this thread](https://www.mothur.org/forum/posting.php?mode=quote&f=3&p=21027):

> [@pschloss](#):
>
> Do not remove singletons. This is based on a mistaken idea and introduces various biases depending on how you do it. Let rarefaction do the correction for you.
> 
> Pat

Is that the general idea now or is it only applicable for the rarefaction calculation in that question?

Cheers,  
Xabi

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**Author:** ![Kendra](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.mothur.org/kendra/32/112_2.png) [@Kendra](https://forum.mothur.org/u/Kendra)\
**Post date:** [November 10, 2017, 8:42pm UTC](https://forum.mothur.org/t/singletons/3441/2 "2017-11-10T20:42:27Z")

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I completely agree with Pat on this. There is no reason that singletons are more likely to be bad sequences than common sequences (remember we are PCRing to generate these data). Removing singletons to improve read quality is a random sledge hammer-maybe you’ll get rid of bad sequences, for sure you’ll get rid of good sequences.