# Resources for using classify-consensus-blast on 16S data

**URL:** https://forum.qiime2.org/t/resources-for-using-classify-consensus-blast-on-16s-data/15504
**Category:** Silva
**Tags:** taxonomy, feature-classifier, silva, greengenes
**Created:** [June 25, 2020, 11:15pm UTC](https://forum.qiime2.org/t/resources-for-using-classify-consensus-blast-on-16s-data/15504 "2020-06-25T23:15:34Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![Nicholas\_Bokulich](https://forum.qiime2.org/user_avatar/forum.qiime2.org/nicholas_bokulich/32/19937_2.png) [@Nicholas\_Bokulich](https://forum.qiime2.org/u/Nicholas_Bokulich)
#### Post date: [June 26, 2020, 5:37pm UTC](https://forum.qiime2.org/t/resources-for-using-classify-consensus-blast-on-16s-data/15504/2 "2020-06-26T17:37:58Z")

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> [@emmzee](#):
>
> I am still not convinced to use sklearn, as I don’t find it straightforward.

I hear your concern. Sometimes complexity is good, though. We designed and optimized the classify-sklearn method to work "out of the box" so that you can use the default settings and get reasonable results without the need for a user to adjust the settings or intimately understand how it works.

Still, I get it if you'd rather use something you have better control over. In that case I recommend using the `classify-consensus-vsearch` method, which is just much better than `classify-consensus-blast`, and has more features to give you _more control_.

See here for more description of all of these methods, and benchmarking results:

> **[Optimizing taxonomic classification of marker-gene amplicon sequences with...](https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-018-0470-z)**
>
> Background Taxonomic classification of marker-gene sequences is an important step in microbiome analysis. Results We present q2-feature-classifier ( https://github.com/qiime2/q2-feature-classifier ), a QIIME 2 plugin containing several novel...

> [@emmzee](#):
>
> My question is, are there any resources available for SILVA or greengenes to use with BLAST consensus classifications on Q2 (i.e. separated reference sequences and associated taxonomy files)?

Yes, on the same [data resources page](https://docs.qiime2.org/2020.2/data-resources/) where the pretrained classifiers are found.

But I recommend waiting until next week when the next release of QIIME 2 comes out, and then take a look at the [2020.6 release data resources](https://docs.qiime2.org/2020.6/data-resources/). The SILVA database files were built in a better way, using [RESCRIPt](https://forum.qiime2.org/t/processing-filtering-and-evaluating-reference-sequence-data-with-rescript/15494)

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