# MOCK sample and PCR blanks

**URL:** https://forum.qiime2.org/t/mock-sample-and-pcr-blanks/1113
**Category:** User Support
**Tags:** filtering
**Created:** [August 29, 2017, 11:08pm UTC](https://forum.qiime2.org/t/mock-sample-and-pcr-blanks/1113 "2017-08-29T23:08:13Z")
**Posts on this page:** 1
**Showing post:** 10

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### Author: ![thermokarst](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/t/8e7dd6/32.png) [@thermokarst](https://forum.qiime2.org/u/thermokarst)
#### Post date: [October 2, 2017, 9:40pm UTC](https://forum.qiime2.org/t/mock-sample-and-pcr-blanks/1113/10 "2017-10-02T21:40:15Z")

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Hi @fstudart!

> [@fstudart](#):
>
> do I also have to remove the same sequences from rep-seqs.qza?

You could probably get away with not removing those features, but your phylogenetic tree will have some extra tips in it, which may or may not impact downstream analyses.

> [@fstudart](#):
>
> if so, is that possible

Yes! As I [mentioned above](https://forum.qiime2.org/t/mock-sample-and-pcr-blanks/1113/6), we now support this kind of filtering in QIIME 2 2017.9. Check out [the docs](https://docs.qiime2.org/2017.9/plugins/available/feature-table/filter-seqs/) for some more info on how to perform this, and let us know if you have any questions.

> [@fstudart](#):
>
> Because, I’ll use this file later on in the analysis to build the tree.

I would suggest trying building a tree and running your analyses both ways (with and without filtering), and see how the results compare, that way you can be confident you are making the right decision.

Thanks! 🦖

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