# extract-reads to train classifier with more than 1 primer pair

**URL:** https://forum.qiime2.org/t/extract-reads-to-train-classifier-with-more-than-1-primer-pair/22311
**Category:** User Support
**Tags:** feature-classifier
**Created:** [February 25, 2022, 10:47pm UTC](https://forum.qiime2.org/t/extract-reads-to-train-classifier-with-more-than-1-primer-pair/22311 "2022-02-25T22:47:25Z")
**Posts on this page:** 1
**Showing post:** 2

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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: [February 25, 2022, 11:25pm UTC](https://forum.qiime2.org/t/extract-reads-to-train-classifier-with-more-than-1-primer-pair/22311/2 "2022-02-25T23:25:46Z")

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Hi @Gaurav_C,

SILVA has two sets of files, one for SSU and another for LSU. The SSU contains both the 16S & 18S sequences. Fortunately, we've made a great plugin to help you curate your own reference database: [RESCRIPt](https://github.com/bokulich-lab/RESCRIPt). You work through this [SILVA tutorial](https://forum.qiime2.org/t/processing-filtering-and-evaluating-the-silva-database-and-other-reference-sequence-data-with-rescript/15494).

You can either make two different classifiers based on your amplicon region or simply use the premade full-length classifier available on the [Data resources](https://docs.qiime2.org/2022.2/data-resources/) page. Check out this [post](https://forum.qiime2.org/t/how-do-i-recover-18s-reads-after-filtering-in-qiime-2/4205/3) for more details.

-Cheers!  
-Mike

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