Each Infinium BeadChip has a unique DMAP file, generated when the BeadChip is manufactured, which includes the location and identity of each beadtype on the array. The location of each beadtype is combined with the quantification of the signal associated with each bead as the BeadChip is scanned to generate the intensity data (.idat) files for each sample. The DMAP file is essential for processing Infinium BeadChip.

The expiration date of BeadChips is one (1) year from the date of manufacture. Illumina retains and provides access to DMAP files for one (1) year past the BeadChip expiration date. If the DMAP file is not downloaded within two (2) years after the BeadChip manufacture date, analysis of the BeadChip is not possible because the DMAP is no longer available.

In the past, DMAP files could be accessed two (2) years after the date of BeadChip manufacture, though this access was not guaranteed. Illumina is changing the physical maintenance of the files on Illumina servers, such that the files will no longer be available beyond the two (2) year retention period.

This change takes effect August 2, 2021 and includes all Infinium Array versions, including commercial, semi-custom, custom, and consortia products.

Illumina is making this change to improve operations and performance of DMAP downloads. Illumina is committed to providing the highest-quality service and support during this change process.

For questions or concerns, contact Illumina Technical Support at techsupport@illumina.com.