# Additional normalization for Maaslin3 if Metatranscriptomics is within taxon scaled

**URL:** <https://forum.biobakery.org/t/additional-normalization-for-maaslin3-if-metatranscriptomics-is-within-taxon-scaled/8813>\
**Category:** MaAsLin\
**Created:** [March 4, 2026, 7:12pm UTC](https://forum.biobakery.org/t/additional-normalization-for-maaslin3-if-metatranscriptomics-is-within-taxon-scaled/8813 "2026-03-04T19:12:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Matthew\_Bolino](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/matthew_bolino/32/3705_2.png) [@Matthew\_Bolino](https://forum.biobakery.org/u/Matthew_Bolino)\
**Post date:** [March 4, 2026, 7:12pm UTC](https://forum.biobakery.org/t/additional-normalization-for-maaslin3-if-metatranscriptomics-is-within-taxon-scaled/8813/1 "2026-03-04T19:12:01Z")

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I am currently using MaAsLin3 for meta-transcriptomic data (CoPM) thats been within taxon scaled (M3 approach). I have MaAsLin3 normalization set to “none”, is this the correct approach?

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**Author:** ![WillNickols](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/willnickols/32/3223_2.png) [@WillNickols](https://forum.biobakery.org/u/WillNickols)\
**Post date:** [March 4, 2026, 7:57pm UTC](https://forum.biobakery.org/t/additional-normalization-for-maaslin3-if-metatranscriptomics-is-within-taxon-scaled/8813/2 "2026-03-04T19:57:51Z")

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Are you sure you mean M3? It sounds like you [might be describing M2](https://github.com/biobakery/biobakery/wiki/MTX-model-3). Either way, you’d want to scale it first and then put it in with normalization set to none. (When you scale within each taxa, your total abundance should be equal to the total number of taxa rather than 1, which is what would happen if you then used the default TSS.)

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**Author:** ![Matthew\_Bolino](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/matthew_bolino/32/3705_2.png) [@Matthew\_Bolino](https://forum.biobakery.org/u/Matthew_Bolino)\
**Post date:** [March 4, 2026, 8:29pm UTC](https://forum.biobakery.org/t/additional-normalization-for-maaslin3-if-metatranscriptomics-is-within-taxon-scaled/8813/3 "2026-03-04T20:29:10Z")

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Hi Will, I see that it is actually M2 (I did not use a taxon RNA covariate). Thank you for your help!