# ITS in q2 - Filtering samples
**URL:** https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702
**Category:** User Support
**Created:** [April 29, 2020, 10:16pm UTC](https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702 "2020-04-29T22:16:17Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@aoliveira](https://forum.qiime2.org/u/aoliveira)
#### Post date: [April 29, 2020, 10:16pm UTC](https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702/1 "2020-04-29T22:16:17Z")
Hi all,
I was left with a doubt regarding the analysis of the ITS data, I am using Qiime2. After Decontam I would like to know if it is correct to use uchime to remove Chimeras as you describe in [Identifying and filtering chimeric feature sequences with vsearch](https://forum.qiime2.org/t/identifying-and-filtering-chimeric-feature-sequences-with-vsearch/2252) or not. Only the dada2 is suficient?
Excuse me if asking is simple, I am starting with q2 has little time.
Thank you for assistance
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### Author:  [@Nicholas\_Bokulich](https://forum.qiime2.org/u/Nicholas_Bokulich)
#### Post date: [April 30, 2020, 5:52pm UTC](https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702/2 "2020-04-30T17:52:20Z")
Welcome to the forum @aoliveira!
If you are using dada2, you do not need to use subsequent chimera filtering, as the methods in q2-dada2 include a chimera filtering step.
If you are using OTU clustering (following that q2-vsearch tutorial) instead of denoising methods, you should include a chimera filtering step. If you are using dada2 for denoising, there is no need to follow that tutorial, as it is for a different type of workflow.
This example — of denoising vs. OTU methods — is one example of how QIIME 2 hosts many different methods, and many different possible workflows. The wealth of possibilities can be confusing and overwhelming! While it is not an exhaustive tutorial, I recommend reading the "overview tutorial" and others at [qiime2.org](http://qiime2.org) to get a sense of the different workflows possible for amplicon sequence analysis with QIIME 2, and how selection of different pathways (e.g., OTU clustering or denoising) have different recommended steps.
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### Author:  [@aoliveira](https://forum.qiime2.org/u/aoliveira)
#### Post date: [April 30, 2020, 11:19pm UTC](https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702/3 "2020-04-30T23:19:19Z")
Thank you so much for your help @Nicholas_Bokulich
I used the "Denoising" method and the reading was complementary to understand that there is no single workflow.
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### Author:  [@system](https://forum.qiime2.org/u/system)
#### Post date: [June 1, 2020, 5:19am UTC](https://forum.qiime2.org/t/its-in-q2-filtering-samples/14702/4 "2020-06-01T05:19:21Z")
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