# Targeting transcriptionally silent gene **URL:** \ **Category:** Gene-editing Discussion\ **Created:** [May 27, 2023, 6:00am UTC](https://forum.allencell.org/t/targeting-transcriptionally-silent-gene/633 "2023-05-27T06:00:25Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Pratiksha](https://avatars.discourse-cdn.com/v4/letter/p/cab0a1/32.png) [@Pratiksha](https://forum.allencell.org/u/Pratiksha)\ **Post date:** [May 27, 2023, 6:00am UTC](https://forum.allencell.org/t/targeting-transcriptionally-silent-gene/633/1 "2023-05-27T06:00:25Z")
We have tried to target a transcriptionally silent gene with a reporter and antibiotic-resistant gene as a selection marker. We see confirmed integration of the cassette but no expression of the reporter upon differentiation. Is there a possibility that the antibiotic resistance gene is affecting the expression of the reporter? ---
**Author:** ![Janani](https://avatars.discourse-cdn.com/v4/letter/j/f14d63/32.png) [@Janani](https://forum.allencell.org/u/Janani)\ **Post date:** [June 1, 2023, 9:41pm UTC](https://forum.allencell.org/t/targeting-transcriptionally-silent-gene/633/2 "2023-06-01T21:41:39Z")
Hi Pratiksha, Thank you. We will need some more information about this experiment. Was selection performed? Could you maybe please share a map of the construct? Thanks, Janani ---
**Author:** ![Pratiksha](https://avatars.discourse-cdn.com/v4/letter/p/cab0a1/32.png) [@Pratiksha](https://forum.allencell.org/u/Pratiksha)\ **Post date:** [June 2, 2023, 5:58am UTC](https://forum.allencell.org/t/targeting-transcriptionally-silent-gene/633/3 "2023-06-02T05:58:23Z")
Thank you for the reply. Our selection marker is puromycin resistant gene. The selection was performed for 10 days. Please find the attached vector map. This segment was cloned into a pBSK vector backbone. ![HDR map](https://canada1.discourse-cdn.com/flex027/uploads/allencell/original/1X/d7007b9cf340d059c635325181990bd8bd91eab7.png)