# 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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