# SUPT1 cell line ploidy

**URL:** <https://forum.depmap.org/t/supt1-cell-line-ploidy/573>\
**Category:** Q&A\
**Created:** [April 22, 2021, 6:17pm UTC](https://forum.depmap.org/t/supt1-cell-line-ploidy/573 "2021-04-22T18:17:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![lauksa](https://avatars.discourse-cdn.com/v4/letter/l/8e7dd6/32.png) [@lauksa](https://forum.depmap.org/u/lauksa)\
**Post date:** [April 22, 2021, 6:17pm UTC](https://forum.depmap.org/t/supt1-cell-line-ploidy/573/1 "2021-04-22T18:17:45Z")

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Hi,

I was exploring copy number (absolute) data and more specific copy number changes of SUPT1 cells. Manual of these cells tells that they have tetraploid genome, however when I explored data and downloaded the absolute copynumber data, the ploidy of this cells line is ~2. Could you clarify why it is ~2 or have I understand something wrong? Other cell line I explored had correct ploidies.

Thank you in advance!

Best,  
Laura

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**Author:** ![jnoorbak](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.depmap.org/jnoorbak/32/12_2.png) [@jnoorbak](https://forum.depmap.org/u/jnoorbak)\
**Post date:** [April 22, 2021, 8:30pm UTC](https://forum.depmap.org/t/supt1-cell-line-ploidy/573/2 "2021-04-22T20:30:01Z")

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Hi. Can you explain a bit on how you determined tetraploidy in this line? -thanks

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**Author:** ![lauksa](https://avatars.discourse-cdn.com/v4/letter/l/8e7dd6/32.png) [@lauksa](https://forum.depmap.org/u/lauksa)\
**Post date:** [April 23, 2021, 9:31am UTC](https://forum.depmap.org/t/supt1-cell-line-ploidy/573/3 "2021-04-23T09:31:52Z")

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Hi jnoorbak,

We have not determided it by ourselves, but we have read it from this references:  
[https://www.lgcstandards-atcc.org/Products/All/CRL-1942.aspx?geo\_country=fi#](https://www.lgcstandards-atcc.org/Products/All/CRL-1942.aspx?geo_country=fi#)  
[https://www.dsmz.de/collection/catalogue/details/culture/ACC-140](https://www.dsmz.de/collection/catalogue/details/culture/ACC-140)  
The Leukemia-Lymphoma Cell Line FactsBook by Hans G Drexler, page 405

From your data portal I downloaded CCLE\_ABSOLUTE\_combined\_20181227.xlsx, and in its tab called “ABSOLUTE\_combined.table” ploidy for sample SUPT1\_HAEMATOPOIETIC\_AND\_LYMPHOID\_TISSUE ACH-000953 is 1.98.

Thank you!

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**Author:** ![jnoorbak](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.depmap.org/jnoorbak/32/12_2.png) [@jnoorbak](https://forum.depmap.org/u/jnoorbak)\
**Post date:** [April 29, 2021, 7:14pm UTC](https://forum.depmap.org/t/supt1-cell-line-ploidy/573/4 "2021-04-29T19:14:21Z")

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looking at the sources you shared it seems like the lines is hypotetraploid, so I’m guessing the overall ploidy should be between 2-4. We rely on ABSOLUTE inferences for these and they are not always accurate. It is possible that the algorithm has missed this case.