# How to merge or generate FASTA file with the same chromosome

**URL:** <https://help.galaxyproject.org/t/how-to-merge-or-generate-fasta-file-with-the-same-chromosome/190>\
**Category:** usegalaxy.org support\
**Tags:** devops-administration, quality-control\
**Created:** [December 12, 2018, 5:21pm UTC](https://help.galaxyproject.org/t/how-to-merge-or-generate-fasta-file-with-the-same-chromosome/190 "2018-12-12T17:21:44Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![jennaj](https://sea2.discourse-cdn.com/flex020/user_avatar/help.galaxyproject.org/jennaj/32/27_2.png) [@jennaj](https://help.galaxyproject.org/u/jennaj)\
**Post date:** [December 12, 2018, 11:34pm UTC](https://help.galaxyproject.org/t/how-to-merge-or-generate-fasta-file-with-the-same-chromosome/190/6 "2018-12-12T23:34:26Z")

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I’m not quite sure I understand but it sounds like you are trying to build a new reference transcriptome (or other “-ome”). If so, it may help to review the Galaxy tutorials.

> [@Troubleshooting resources for errors or unexpected results](https://help.galaxyproject.org/t/troubleshooting-resources-for-errors-or-unexpected-results/42/1):
>
> [Galaxy Training Network Tutorials](https://galaxyproject.github.io/training-material/): Some [GTN](https://galaxyproject.org/teach/gtn/) tutorials are appropriate for [Galaxy Main](https://usegalaxy.org) and some are not. Where you can run each is noted per tutorial – click on the _Galaxy instances_ gear icon ![galaxyserversGTN](https://us1.discourse-cdn.com/flex020/uploads/galaxy/original/1X/1287f50cfcdaa1aad750fe323f96995260ac4947.png) to review the [Public Galaxy](https://galaxyproject.org/use/) server choices. If a tutorial is supported by a pre-configured [Galaxy Docker](https://hub.docker.com/r/bgruening/galaxy-stable/) training image, instructions for how to get it will be listed below the tutorial listings, per category.

_Note_: It is technically possible to rename identifiers in any dataset but some are more difficult to transform than others. And all datasets used together in visualization or other analysis steps need to have the identifiers (that represent the exact same underlying data) modified with a precision method that fits the different datatypes involved. I wouldn’t recommend that anyone attempts modifications like this unless they already know how to do it and are able to detect plus troubleshoot any problems that might come up. The steps are too complicated (especially with BAM data) and much can go wrong. This is why I think that starting over with the identifiers you want to use at the beginning, then working through your analysis with consistent data for all steps, is the best approach. All will go much smoother!

Since you are starting over, this might be a good time to consider updating the workflow you shared. It uses older versions of a few tools. Using the latest versions of tools is always better. Tools can be updated within the workflow editor.

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_[View the full topic](https://help.galaxyproject.org/t/how-to-merge-or-generate-fasta-file-with-the-same-chromosome/190)._