# Taxonomy assignment using Silva 138

**URL:** https://forum.qiime2.org/t/taxonomy-assignment-using-silva-138/25967
**Category:** Silva
**Tags:** taxonomy, feature-classifier, silva
**Created:** [March 29, 2023, 2:49pm UTC](https://forum.qiime2.org/t/taxonomy-assignment-using-silva-138/25967 "2023-03-29T14:49:43Z")
**Posts on this page:** 1
**Showing post:** 11

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### Author: ![SoilRotifer](https://forum.qiime2.org/user_avatar/forum.qiime2.org/soilrotifer/32/21071_2.png) [@SoilRotifer](https://forum.qiime2.org/u/SoilRotifer)
#### Post date: [March 30, 2023, 7:33pm UTC](https://forum.qiime2.org/t/taxonomy-assignment-using-silva-138/25967/11 "2023-03-30T19:33:00Z")

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Hi @emmlemore,

> [@emmlemore](#):
>
> I guess my next option would be the RESCRIPt option?

Potentially. After extracting your amplicon region did you dereplicate the data as outlined [here](https://forum.qiime2.org/t/processing-filtering-and-evaluating-the-silva-database-and-other-reference-sequence-data-with-rescript/15494#heading--sixth-header)? If not, this might be partly responsible the excessive memory despite using the extracted amplicon region. That is, many reference sequences will become identical over the smaller span of the amplicon region. Dereplication will remove any redundant sequences with identical taxonomy, which can be substantial. You can also perform other optional filtering of your reference data too.

Alternatively, you may want to consider using `feature-classifier classify-consensus-vsearch`, just simply use the base sequence and taxonomy files that you'd train your classifier with, as your reference data. Otherwise you may need to find a machine with more RAM.

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