# Are custom primers recoverable after loading into the iSeq 100 reagent cartridge?

No. Loading custom primers into the iSeq 100 reagent cartridge involves loading of the primer(s) into read-specific reservoirs within the cartridge. Additionally, pre-run checks are performed on the dry flow cell and reagent cartridge for custom primer runs prior to any addition of primer or library. Once the pre-run checks begin, the reagent cartridge and flow cell are marked as used. There is no workaround to salvage consumables that have been marked as used.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #6505), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000006505%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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