# PRISM Batch effect

**URL:** <https://forum.depmap.org/t/prism-batch-effect/3439>\
**Category:** Issues and Bugs\
**Tags:** compound-screens\
**Created:** [July 19, 2024, 12:43pm UTC](https://forum.depmap.org/t/prism-batch-effect/3439 "2024-07-19T12:43:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![bav](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@bav](https://forum.depmap.org/u/bav)\
**Post date:** [July 19, 2024, 12:43pm UTC](https://forum.depmap.org/t/prism-batch-effect/3439/1 "2024-07-19T12:43:46Z")

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Hi DepMap!

I noticed what appears to be a batch effect, and wanted to share - Plotted below are the median PRISM LFCs (primary screen), across all compounds, sorted on DepMap\_ID (accessed from the Custom Downloads interface). Samples with DepMap ID \> ~ACH-0001000 seem to have greater median sensitivity.

 ![Screenshot 2024-07-19 at 8.39.54 AM](https://canada1.discourse-cdn.com/flex035/uploads/depmap/original/2X/e/e6f6be3fc1aa01bb3743e273d165e557a5b54dab.png)

best regards - Brendan