# Documentation on Addtional Reference Data

**URL:** <https://community.brain-map.org/t/documentation-on-addtional-reference-data/4244>\
**Category:** Science\
**Created:** [March 13, 2025, 4:50pm UTC](https://community.brain-map.org/t/documentation-on-addtional-reference-data/4244 "2025-03-13T16:50:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![karton](https://avatars.discourse-cdn.com/v4/letter/k/e9c0ed/32.png) [@karton](https://community.brain-map.org/u/karton)\
**Post date:** [March 13, 2025, 4:50pm UTC](https://community.brain-map.org/t/documentation-on-addtional-reference-data/4244/1 "2025-03-13T16:50:03Z")

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Hi,

I’m looking for documentation on the Additional Reference Data for the Developing Mouse Brain. Specifically, I am trying to find the slice thickness and interval for the E16.5 coronal brain.

Thanks!

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**Author:** ![JNyhus](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JNyhus](https://community.brain-map.org/u/JNyhus)\
**Post date:** [March 13, 2025, 5:17pm UTC](https://community.brain-map.org/t/documentation-on-addtional-reference-data/4244/2 "2025-03-13T17:17:30Z")

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Hi karton,  
Section thickness is 20 micron for the earlier timepoints up to P4 and 25 micron for P14 and older (section thickness is an attribute of the SectionDataSet object)

The interval varies by developmental stage and can be found here: [Developing Mouse Reference Atlas - How To / Allen Developing Mouse Brain Atlas - Allen Brain Map Community Forum](https://community.brain-map.org/t/developing-mouse-reference-atlas/2852)

Thanks for your interest in the Atlas,  
J