# Allen Mouse In Situ Hybridization Data **URL:** \ **Category:** How To\ **Created:** [August 9, 2023, 6:51pm UTC](https://community.brain-map.org/t/allen-mouse-in-situ-hybridization-data/2541 "2023-08-09T18:51:20Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![MPanday](https://avatars.discourse-cdn.com/v4/letter/m/49beb7/32.png) [@MPanday](https://community.brain-map.org/u/MPanday)\ **Post date:** [August 9, 2023, 6:51pm UTC](https://community.brain-map.org/t/allen-mouse-in-situ-hybridization-data/2541/1 "2023-08-09T18:51:20Z")
Hi there, I’m using the Allen Institute’s mouse ISH data for a project and I wanted to ask about the numbering of individual sections within an experiment. If I take the coronal section dataset for MBP RNA ISH, I notice the experiment ID is 112202838 whereas there are individual coronal sections labelled 112202923, 112202925, 112202927 and so on. Do the last three digits have any significance (i.e., are they the distance in microns of that slice relative to a specific anatomical landmark)? Figured I’d ask how these data were numbered and whether there’s any significant convention to the numbering system used there. Thanks for the help. ---
**Author:** ![racheld](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.brain-map.org/racheld/32/107_2.png) [@racheld](https://community.brain-map.org/u/racheld)\ **Post date:** [August 30, 2023, 12:17am UTC](https://community.brain-map.org/t/allen-mouse-in-situ-hybridization-data/2541/2 "2023-08-30T00:17:43Z")
Hello @MPanday I think you will find our [White Paper](http://help.brain-map.org/download/attachments/2818169/ABADataProductionProcesses.pdf?version=1&modificationDate=1319477154403&api=v2) immensely handy. Specifically see page nine where it discusses the spacing of our coronal ISH image series. The ending digits imply sequential order with distance specified in the White Paper. If you notice a larger than normal gap you can assume a section was failed. Thanks for your question.